From 72bf900142eda8e4a841beb07940bb57b39fb2c6 Mon Sep 17 00:00:00 2001
From: Julien Jerphanion <git@jjerphan.xyz>
Date: Fri, 7 Aug 2026 16:46:06 +0200
Subject: [PATCH 1/8] Have `numpy` use `openblas` for BLAS and LAPACK

Signed-off-by: Julien Jerphanion <git@jjerphan.xyz>
---
 recipes/recipes_emscripten/numpy/build.sh    | 12 +++++++++---
 recipes/recipes_emscripten/numpy/recipe.yaml |  6 +++++-
 2 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/recipes/recipes_emscripten/numpy/build.sh b/recipes/recipes_emscripten/numpy/build.sh
index 5b26306b9c9..bb609c86a08 100644
--- a/recipes/recipes_emscripten/numpy/build.sh
+++ b/recipes/recipes_emscripten/numpy/build.sh
@@ -1,15 +1,20 @@
 #!/bin/bash
 
+set -ex
+
 echo "PYTHON"
 
 rm -r -f branding
 
+# necessary for cross-compilation to point to the right env
+export PKG_CONFIG_PATH=$PREFIX/lib/pkgconfig
+
 export CFLAGS="$CFLAGS -Wno-return-type -Wno-implicit-function-declaration -msimd128 -fwasm-exceptions -s SUPPORT_LONGJMP"
-export MESON_CROSS_FILE=$RECIPE_DIR/emscripten.meson.cross 
+export MESON_CROSS_FILE=$RECIPE_DIR/emscripten.meson.cross
 export LDFLAGS="$LDFLAGS -sWASM_BIGINT 	-s WASM_BIGINT -fwasm-exceptions -s SUPPORT_LONGJMP"
 
 cp $RECIPE_DIR/config/config.h.in  numpy/_core/config.h.in
-# 
+#
 
 # otherwise "cython" is not properly executable
 echo "add shebang to cython file"
@@ -22,5 +27,6 @@ sed -i 's/-fexceptions/-fwasm-exceptions/g' numpy/_core/meson.build
 
 
 MESON_ARGS="-Dhave_backtrace=false" ${PYTHON} -m pip install . -vvv --no-deps --no-build-isolation \
-    -Csetup-args="-Dallow-noblas=true" \
+    -Csetup-args="-Dblas=openblas" \
+    -Csetup-args="-Dlapack=openblas" \
     -Csetup-args="--cross-file=$MESON_CROSS_FILE"
diff --git a/recipes/recipes_emscripten/numpy/recipe.yaml b/recipes/recipes_emscripten/numpy/recipe.yaml
index 62346d5e6c3..4a3e146dc6e 100644
--- a/recipes/recipes_emscripten/numpy/recipe.yaml
+++ b/recipes/recipes_emscripten/numpy/recipe.yaml
@@ -11,7 +11,7 @@ source:
   url: https://github.com/numpy/numpy/releases/download/v${{ version }}/numpy-${{ version }}.tar.gz
   sha256: a48a113e6afea91f5608793bafa7ef2ad481fefbda87ec5069f483de61cb9fa3
 build:
-  number: 0
+  number: 1
 
   files:
     exclude:
@@ -35,6 +35,10 @@ requirements:
   - pkg-config
   - python
   host:
+  - openblas
+  - python
+  run:
+  - openblas
   - python
   run_exports:
   - numpy >=${{ default_abi_level }},<3

From 113bc7e623855b8937ce52278d067ae15ba11411 Mon Sep 17 00:00:00 2001
From: Julien Jerphanion <git@jjerphan.xyz>
Date: Fri, 7 Aug 2026 17:21:53 +0200
Subject: [PATCH 2/8] Add test on BLAS and LAPACK code paths

Signed-off-by: Julien Jerphanion <git@jjerphan.xyz>
---
 .../recipes_emscripten/numpy/test_numpy.py    | 49 +++++++++++++++++--
 1 file changed, 46 insertions(+), 3 deletions(-)

diff --git a/recipes/recipes_emscripten/numpy/test_numpy.py b/recipes/recipes_emscripten/numpy/test_numpy.py
index 839ca268a61..62e0259e3bb 100644
--- a/recipes/recipes_emscripten/numpy/test_numpy.py
+++ b/recipes/recipes_emscripten/numpy/test_numpy.py
@@ -1,5 +1,48 @@
+import numpy as np
+from numpy.testing import assert_allclose
+
+
 def test_numpy():
-    import numpy
+    ones = np.ones(shape=[2, 3])
+    assert ones.shape == (2, 3)
+
+
+# Large enough that OpenBLAS blocked kernels are exercised (not tiny fallbacks).
+N = 300
+
+
+def test_blas_matmul():
+    rng = np.random.default_rng(0)
+    a = rng.standard_normal((N, N))
+    b = rng.standard_normal((N, N))
+    c = a @ b
+    assert c.shape == (N, N)
+    assert_allclose(c, np.dot(a, b))
+    assert_allclose(c.T, b.T @ a.T)
+
+
+def test_lapack_cholesky():
+    rng = np.random.default_rng(1)
+    x = rng.standard_normal((N, N))
+    a = x @ x.T + N * np.eye(N)
+    l = np.linalg.cholesky(a)
+    assert_allclose(l @ l.T, a)
+
+
+def test_lapack_solve():
+    rng = np.random.default_rng(2)
+    a = rng.standard_normal((N, N))
+    b = rng.standard_normal(N)
+    x = np.linalg.solve(a, b)
+    assert_allclose(a @ x, b)
+
 
-    ones = numpy.ones(shape=[2,3])
-    assert ones.shape == (2,3)
\ No newline at end of file
+def test_lapack_eigh():
+    rng = np.random.default_rng(3)
+    x = rng.standard_normal((N, N))
+    a = x @ x.T
+    evals, evecs = np.linalg.eigh(a)
+    assert evals.shape == (N,)
+    assert evecs.shape == (N, N)
+    assert_allclose(evecs.T @ evecs, np.eye(N), atol=1e-8)
+    assert_allclose(evecs @ np.diag(evals) @ evecs.T, a)

From ff840ca7760e4c06cb805cac41870276cbd3dcdb Mon Sep 17 00:00:00 2001
From: Julien Jerphanion <git@jjerphan.xyz>
Date: Mon, 10 Aug 2026 10:13:45 +0200
Subject: [PATCH 3/8] Build and link against OpenBLAS

Signed-off-by: Julien Jerphanion <git@jjerphan.xyz>
---
 recipes/recipes_emscripten/numpy/build.sh     |  62 ++++-
 .../numpy/emscripten.meson.cross              |   2 +-
 .../numpy/fix_flang_fortran_abi.py            | 225 ++++++++++++++++++
 .../recipes_emscripten/numpy/test_numpy.py    |  12 +
 4 files changed, 293 insertions(+), 8 deletions(-)
 create mode 100644 recipes/recipes_emscripten/numpy/fix_flang_fortran_abi.py

diff --git a/recipes/recipes_emscripten/numpy/build.sh b/recipes/recipes_emscripten/numpy/build.sh
index bb609c86a08..cad7c494d15 100644
--- a/recipes/recipes_emscripten/numpy/build.sh
+++ b/recipes/recipes_emscripten/numpy/build.sh
@@ -6,27 +6,75 @@ echo "PYTHON"
 
 rm -r -f branding
 
-# necessary for cross-compilation to point to the right env
-export PKG_CONFIG_PATH=$PREFIX/lib/pkgconfig
+# OpenBLAS must be visible to Meson via pkg-config during the cross build.
+# Channel packages may still embed the original build-machine placeholder
+# paths in openblas.pc; write corrected .pc files into a build-local
+# pkgconfig dir (not $PREFIX — that would ship them in the numpy package).
+#
+# Also install a scipy-openblas.pc alias. NumPy prefers that name and looks
+# it up with plain pkg-config (same pattern as SciPy). That bypasses Meson's
+# packages['openblas'] factory, whose void dgemm_()/cblas_dgemm() symbol
+# probes fail under wasm-ld signature matching against flang-built OpenBLAS.
+PKGCONFIG_DIR="${SRC_DIR}/.emscripten-pkgconfig"
+mkdir -p "${PKGCONFIG_DIR}"
+for pc_name in openblas scipy-openblas; do
+  cat > "${PKGCONFIG_DIR}/${pc_name}.pc" <<EOF
+prefix=${PREFIX}
+libdir=\${prefix}/lib
+includedir=\${prefix}/include
+openblas_config=USE_THREAD=0 TARGET=RISCV64_GENERIC
+version=0.3.31
+Name: ${pc_name}
+Description: OpenBLAS is an optimized BLAS library based on GotoBLAS2 1.13 BSD version
+Version: \${version}
+Libs: -L\${libdir} -lopenblas
+Cflags: -I\${includedir}
+EOF
+done
+
+export PKG_CONFIG_PATH="${PKGCONFIG_DIR}${PKG_CONFIG_PATH:+:${PKG_CONFIG_PATH}}"
+
+# Fail early if OpenBLAS is not usable from pkg-config.
+pkg-config --exists --print-errors openblas
+pkg-config --exists --print-errors scipy-openblas
+pkg-config --cflags --libs openblas
+test -f "${PREFIX}/include/cblas.h"
+test -f "${PREFIX}/lib/libopenblas.so"
+
+# Point Meson's host pkg-config search at the build-local .pc files (cross
+# builds do not always inherit PKG_CONFIG_PATH the way native builds do).
+cp "${RECIPE_DIR}/emscripten.meson.cross" "${SRC_DIR}/emscripten.meson.cross"
+cat >> "${SRC_DIR}/emscripten.meson.cross" <<EOF
+
+[built-in options]
+pkg_config_path = ['${PKGCONFIG_DIR}']
+EOF
+export MESON_CROSS_FILE="${SRC_DIR}/emscripten.meson.cross"
 
 export CFLAGS="$CFLAGS -Wno-return-type -Wno-implicit-function-declaration -msimd128 -fwasm-exceptions -s SUPPORT_LONGJMP"
-export MESON_CROSS_FILE=$RECIPE_DIR/emscripten.meson.cross
 export LDFLAGS="$LDFLAGS -sWASM_BIGINT 	-s WASM_BIGINT -fwasm-exceptions -s SUPPORT_LONGJMP"
 
 cp $RECIPE_DIR/config/config.h.in  numpy/_core/config.h.in
-#
 
 # otherwise "cython" is not properly executable
 echo "add shebang to cython file"
 sed -i '1i#!/usr/bin/env python' $BUILD_PREFIX/bin/cython
 
-
-
 # replace -fexceptions with -fwasm-exceptions in numpy/_core
 sed -i 's/-fexceptions/-fwasm-exceptions/g' numpy/_core/meson.build
 
+# Match flang OpenBLAS Fortran ABI (void returns + CHARACTER length args).
+# Same issue SciPy solves with its char-length / return-type patches.
+${PYTHON} "${RECIPE_DIR}/fix_flang_fortran_abi.py" \
+    numpy/linalg/lapack_litemodule.c \
+    numpy/linalg/umath_linalg.cpp \
+    numpy/linalg/lapack_lite/python_xerbla.c \
+    numpy/_core/src/common/python_xerbla.c
 
-MESON_ARGS="-Dhave_backtrace=false" ${PYTHON} -m pip install . -vvv --no-deps --no-build-isolation \
+# -Dblas=openblas makes NumPy try scipy-openblas first (see numpy/meson.build).
+# allow-noblas defaults to true; force OpenBLAS to be required.
+${PYTHON} -m pip install . -vvv --no-deps --no-build-isolation \
     -Csetup-args="-Dblas=openblas" \
     -Csetup-args="-Dlapack=openblas" \
+    -Csetup-args="-Dallow-noblas=false" \
     -Csetup-args="--cross-file=$MESON_CROSS_FILE"
diff --git a/recipes/recipes_emscripten/numpy/emscripten.meson.cross b/recipes/recipes_emscripten/numpy/emscripten.meson.cross
index 5ef99c56d35..13d8b5fa287 100644
--- a/recipes/recipes_emscripten/numpy/emscripten.meson.cross
+++ b/recipes/recipes_emscripten/numpy/emscripten.meson.cross
@@ -1,6 +1,6 @@
 [binaries]
 exe_wrapper = 'node'
-pkgconfig = 'pkg-config'
+pkg-config = 'pkg-config'
 
 [properties]
 needs_exe_wrapper = true
diff --git a/recipes/recipes_emscripten/numpy/fix_flang_fortran_abi.py b/recipes/recipes_emscripten/numpy/fix_flang_fortran_abi.py
new file mode 100644
index 00000000000..c59a0435936
--- /dev/null
+++ b/recipes/recipes_emscripten/numpy/fix_flang_fortran_abi.py
@@ -0,0 +1,225 @@
+#!/usr/bin/env python3
+"""Adapt NumPy Fortran BLAS/LAPACK wrappers for flang-built OpenBLAS on wasm.
+
+Flang emits Fortran subroutines as returning void and appends a hidden
+character-length argument for each CHARACTER dummy. NumPy's wrappers still
+follow the f2c/g77 convention (int return, no length args). wasm-ld rejects
+the resulting signature mismatches.
+
+Mirrors the approach used in the emscripten-forge SciPy recipe.
+"""
+
+from __future__ import annotations
+
+import re
+import sys
+from pathlib import Path
+
+# Fortran *functions* that must keep a non-void return type.
+KEEP_RETURN = {"sdot", "ddot"}
+
+
+def count_char_params(proto: str) -> int:
+    return len(re.findall(r"\bchar\s*\*", proto))
+
+
+def append_char_lengths(args: str, n: int) -> str:
+    if n <= 0:
+        return args
+    if re.search(r"(?:,\s*1)+\s*$", args):
+        return args
+    return args + "".join(", 1" for _ in range(n))
+
+
+def find_matching_paren(text: str, open_idx: int) -> int:
+    """Return index of the ')' matching text[open_idx] == '('."""
+    depth = 0
+    for i in range(open_idx, len(text)):
+        ch = text[i]
+        if ch == "(":
+            depth += 1
+        elif ch == ")":
+            depth -= 1
+            if depth == 0:
+                return i
+    raise ValueError("unbalanced parentheses")
+
+
+def iter_fortran_calls(text: str):
+    """Yield (start, end, callee, name, args) for FNAME|LAPACK|BLAS(name)(args)."""
+    for m in re.finditer(r"(?:FNAME|LAPACK|BLAS)\((\w+)\)\s*\(", text):
+        name = m.group(1)
+        callee_end = m.end() - 1  # index of '(' starting args
+        # Find start of callee token
+        callee_start = m.start()
+        try:
+            close = find_matching_paren(text, callee_end)
+        except ValueError:
+            continue
+        args = text[callee_end + 1 : close]
+        callee = text[callee_start : callee_end]
+        yield callee_start, close + 1, callee, name, args
+
+
+def is_prototype_args(args: str) -> bool:
+    """True if this argument list looks like a C/C++ prototype, not a call."""
+    if re.search(r"\bchar\s*\*[A-Za-z_]", args):
+        return True
+    if re.search(r"\[[^\]]*\]", args):
+        return True
+    if re.search(r"\b(?:float|double|fortran_int|f2c_\w+)\s+\*?[A-Za-z_]", args):
+        return True
+    if re.search(r",\s*int(\s*,\s*int)*\s*$", args):
+        return True
+    return False
+
+
+def collect_char_counts(text: str) -> dict[str, int]:
+    counts: dict[str, int] = {}
+    for m in re.finditer(r"FNAME\((\w+)\)\s*\(", text):
+        name = m.group(1)
+        open_idx = m.end() - 1
+        try:
+            close = find_matching_paren(text, open_idx)
+        except ValueError:
+            continue
+        proto = text[open_idx + 1 : close]
+        # Only learn from prototypes, never from call sites.
+        if not is_prototype_args(proto):
+            continue
+        counts[name] = count_char_params(proto)
+    return counts
+
+
+def fix_externs(text: str) -> str:
+    """void-ify Fortran subroutine prototypes and append char-length formals."""
+
+    out: list[str] = []
+    i = 0
+    pattern = re.compile(r"extern(?:\s+\"C\")?\s+fortran_int\s+")
+
+    while True:
+        m = pattern.search(text, i)
+        if not m:
+            out.append(text[i:])
+            break
+        out.append(text[i : m.start()])
+        # Expect FNAME(name)(proto);
+        rest = text[m.end() :]
+        fm = re.match(r"FNAME\((\w+)\)\s*\(", rest)
+        if not fm:
+            out.append(text[m.start() : m.end()])
+            i = m.end()
+            continue
+        name = fm.group(1)
+        open_idx = m.end() + fm.end() - 1
+        close = find_matching_paren(text, open_idx)
+        if close + 1 < len(text) and text[close + 1] == ";":
+            end = close + 2
+        else:
+            out.append(text[m.start() : m.end()])
+            i = m.end()
+            continue
+        proto = text[open_idx + 1 : close]
+        if name in KEEP_RETURN:
+            out.append(text[m.start() : end])
+        else:
+            n_char = count_char_params(proto)
+            if n_char:
+                proto = re.sub(r"(?:,\s*int)+$", "", proto)
+                proto = proto + "".join(", int" for _ in range(n_char))
+            # Preserve "extern" / 'extern "C"' prefix and spacing before FNAME.
+            prefix = text[m.start() : m.end()].replace("fortran_int", "void", 1)
+            out.append(f"{prefix}FNAME({name})({proto});")
+        i = end
+
+    return "".join(out)
+
+
+def fix_calls(text: str, char_counts: dict[str, int]) -> str:
+    """Append flang char-length actuals and drop void subroutine return uses."""
+
+    # Process from end to start so indices stay valid.
+    replacements: list[tuple[int, int, str]] = []
+
+    for start, end, callee, name, args in iter_fortran_calls(text):
+        if is_prototype_args(args):
+            continue
+        n = char_counts.get(name, 0)
+        new_args = append_char_lengths(args, n) if n else args
+        new_call = f"{callee}({new_args})"
+
+        # return <call>;
+        before = text[:start].rstrip()
+        after = text[end:].lstrip()
+        if before.endswith("return") and name not in KEEP_RETURN and after.startswith(";"):
+            # Replace `return call;` with `call; return 0;`
+            # Expand to include 'return' and ';'
+            ret_start = text.rfind("return", 0, start)
+            semi = text.find(";", end)
+            replacements.append((ret_start, semi + 1, f"{new_call}; return 0;"))
+            continue
+
+        # lapack_lite_status = <call>;
+        if re.search(r"lapack_lite_status\s*=\s*$", text[:start]) and name not in KEEP_RETURN:
+            assign_start = text.rfind("lapack_lite_status", 0, start)
+            semi = text.find(";", end)
+            replacements.append(
+                (assign_start, semi + 1, f"{new_call};\n        lapack_lite_status = info;")
+            )
+            continue
+
+        if new_args != args:
+            replacements.append((start, end, new_call))
+
+    for start, end, repl in sorted(replacements, reverse=True):
+        text = text[:start] + repl + text[end:]
+    return text
+
+
+def fix_python_xerbla(text: str) -> str:
+    """Match flang OpenBLAS xerbla: void return + character length argument."""
+    text = text.replace(
+        "CBLAS_INT BLAS_FUNC(xerbla)(char *srname, CBLAS_INT *info)",
+        "void BLAS_FUNC(xerbla)(char *srname, CBLAS_INT *info, int srname_len)",
+    )
+    text = re.sub(
+        r"(PyGILState_Release\(save\);\n)\s*return 0;\n(\})",
+        r"\1\2",
+        text,
+    )
+    text = text.replace(
+        "while( len<6 && srname[len]!='\\0' )",
+        "while( len<6 && len<srname_len && srname[len]!='\\0' )",
+    )
+    return text
+
+
+def process_file(path: Path) -> None:
+    original = path.read_text()
+    text = original
+    if path.name == "python_xerbla.c":
+        text = fix_python_xerbla(text)
+    else:
+        char_counts = collect_char_counts(text)
+        text = fix_externs(text)
+        # Recompute after prototype rewrite (names unchanged; counts same).
+        text = fix_calls(text, char_counts)
+    if text == original:
+        print(f"warning: no changes in {path}", file=sys.stderr)
+    else:
+        path.write_text(text)
+        print(f"patched {path}")
+
+
+def main(argv: list[str]) -> int:
+    if len(argv) < 2:
+        print(f"usage: {argv[0]} FILE [FILE...]", file=sys.stderr)
+        return 2
+    for arg in argv[1:]:
+        process_file(Path(arg))
+    return 0
+
+
+if __name__ == "__main__":
+    raise SystemExit(main(sys.argv))
diff --git a/recipes/recipes_emscripten/numpy/test_numpy.py b/recipes/recipes_emscripten/numpy/test_numpy.py
index 62e0259e3bb..469f6aef97e 100644
--- a/recipes/recipes_emscripten/numpy/test_numpy.py
+++ b/recipes/recipes_emscripten/numpy/test_numpy.py
@@ -7,6 +7,18 @@ def test_numpy():
     assert ones.shape == (2, 3)
 
 
+def test_openblas_build_config():
+    cfg = np.show_config(mode="dicts")
+    blas = cfg["Build Dependencies"]["blas"]
+    lapack = cfg["Build Dependencies"]["lapack"]
+    assert blas["found"] is True
+    assert lapack["found"] is True
+    # scipy-openblas.pc alias is used to bypass Meson's OpenBLAS factory.
+    assert "openblas" in blas["name"]
+    assert "openblas configuration" in blas
+    assert blas["openblas configuration"] != "unknown"
+
+
 # Large enough that OpenBLAS blocked kernels are exercised (not tiny fallbacks).
 N = 300
 

From 727504b8b9739bb7fc0204bec8a1f2804d8548f3 Mon Sep 17 00:00:00 2001
From: Julien Jerphanion <git@jjerphan.xyz>
Date: Mon, 10 Aug 2026 11:56:14 +0200
Subject: [PATCH 4/8] Prefer applying a patch

Signed-off-by: Julien Jerphanion <git@jjerphan.xyz>
---
 recipes/recipes_emscripten/numpy/build.sh     |   8 -
 .../numpy/fix_flang_fortran_abi.py            |  54 +-
 ...LAS-Fortran-ABI-on-Emscripten-wasm32.patch | 791 ++++++++++++++++++
 recipes/recipes_emscripten/numpy/recipe.yaml  |   2 +
 4 files changed, 842 insertions(+), 13 deletions(-)
 create mode 100644 recipes/recipes_emscripten/numpy/patches/0001-Match-flang-OpenBLAS-Fortran-ABI-on-Emscripten-wasm32.patch

diff --git a/recipes/recipes_emscripten/numpy/build.sh b/recipes/recipes_emscripten/numpy/build.sh
index cad7c494d15..095d5067bdf 100644
--- a/recipes/recipes_emscripten/numpy/build.sh
+++ b/recipes/recipes_emscripten/numpy/build.sh
@@ -63,14 +63,6 @@ sed -i '1i#!/usr/bin/env python' $BUILD_PREFIX/bin/cython
 # replace -fexceptions with -fwasm-exceptions in numpy/_core
 sed -i 's/-fexceptions/-fwasm-exceptions/g' numpy/_core/meson.build
 
-# Match flang OpenBLAS Fortran ABI (void returns + CHARACTER length args).
-# Same issue SciPy solves with its char-length / return-type patches.
-${PYTHON} "${RECIPE_DIR}/fix_flang_fortran_abi.py" \
-    numpy/linalg/lapack_litemodule.c \
-    numpy/linalg/umath_linalg.cpp \
-    numpy/linalg/lapack_lite/python_xerbla.c \
-    numpy/_core/src/common/python_xerbla.c
-
 # -Dblas=openblas makes NumPy try scipy-openblas first (see numpy/meson.build).
 # allow-noblas defaults to true; force OpenBLAS to be required.
 ${PYTHON} -m pip install . -vvv --no-deps --no-build-isolation \
diff --git a/recipes/recipes_emscripten/numpy/fix_flang_fortran_abi.py b/recipes/recipes_emscripten/numpy/fix_flang_fortran_abi.py
index c59a0435936..f05fce5eded 100644
--- a/recipes/recipes_emscripten/numpy/fix_flang_fortran_abi.py
+++ b/recipes/recipes_emscripten/numpy/fix_flang_fortran_abi.py
@@ -1,12 +1,55 @@
 #!/usr/bin/env python3
-"""Adapt NumPy Fortran BLAS/LAPACK wrappers for flang-built OpenBLAS on wasm.
+"""Helper to regenerate the flang OpenBLAS Fortran ABI patch for NumPy.
 
+Background
+----------
 Flang emits Fortran subroutines as returning void and appends a hidden
 character-length argument for each CHARACTER dummy. NumPy's wrappers still
 follow the f2c/g77 convention (int return, no length args). wasm-ld rejects
-the resulting signature mismatches.
-
-Mirrors the approach used in the emscripten-forge SciPy recipe.
+the resulting signature mismatches when linking against the emscripten-forge
+OpenBLAS package (built with flang-new).
+
+The recipe applies an explicit source patch (SciPy-style), not this script,
+at build time:
+
+  patches/0001-Match-flang-OpenBLAS-Fortran-ABI-on-Emscripten-wasm32.patch
+
+Keep this script around to regenerate that patch when NumPy's Fortran
+wrappers change upstream.
+
+Usage — edit files in place
+---------------------------
+From an extracted NumPy source tree (matching the recipe version)::
+
+  python3 fix_flang_fortran_abi.py \\
+      numpy/linalg/lapack_litemodule.c \\
+      numpy/linalg/umath_linalg.cpp \\
+      numpy/linalg/lapack_lite/python_xerbla.c \\
+      numpy/_core/src/common/python_xerbla.c
+
+Usage — regenerate the recipe patch
+-----------------------------------
+::
+
+  # Extract the same NumPy tarball as in recipe.yaml, then:
+  git init && git add <the four files above> && git commit -m baseline
+  python3 path/to/fix_flang_fortran_abi.py <the four files>
+  git add <the four files>
+  git commit  # use the commit message from the existing .patch Subject/body
+  git format-patch -1 --stdout > \\
+      recipes/recipes_emscripten/numpy/patches/\\
+      0001-Match-flang-OpenBLAS-Fortran-ABI-on-Emscripten-wasm32.patch
+
+What it changes
+---------------
+- Fortran subroutine prototypes: ``fortran_int`` -> ``void``
+- One trailing ``int`` formal per ``char *`` parameter
+- Call sites: pass length actual ``1`` for each CHARACTER argument
+- Drop uses of subroutine return values (``info`` / ``return 0``)
+- ``python_xerbla``: ``void`` return + ``srname_len`` argument
+
+Fortran *functions* that keep a non-void return (``sdot``, ``ddot``) are
+left unchanged.
 """
 
 from __future__ import annotations
@@ -214,7 +257,8 @@ def process_file(path: Path) -> None:
 
 def main(argv: list[str]) -> int:
     if len(argv) < 2:
-        print(f"usage: {argv[0]} FILE [FILE...]", file=sys.stderr)
+        print(__doc__.strip(), file=sys.stderr)
+        print(f"\nusage: {argv[0]} FILE [FILE...]", file=sys.stderr)
         return 2
     for arg in argv[1:]:
         process_file(Path(arg))
diff --git a/recipes/recipes_emscripten/numpy/patches/0001-Match-flang-OpenBLAS-Fortran-ABI-on-Emscripten-wasm32.patch b/recipes/recipes_emscripten/numpy/patches/0001-Match-flang-OpenBLAS-Fortran-ABI-on-Emscripten-wasm32.patch
new file mode 100644
index 00000000000..29913fd154b
--- /dev/null
+++ b/recipes/recipes_emscripten/numpy/patches/0001-Match-flang-OpenBLAS-Fortran-ABI-on-Emscripten-wasm32.patch
@@ -0,0 +1,791 @@
+From b9061352fdcef90e251c12ade776e774558b12f9 Mon Sep 17 00:00:00 2001
+From: Julien Jerphanion <git@jjerphan.xyz>
+Date: Mon, 10 Aug 2026 10:52:43 +0200
+Subject: [PATCH] Match flang OpenBLAS Fortran ABI on Emscripten/wasm32
+
+Linking NumPy against flang-built OpenBLAS fails under wasm-ld because
+NumPy's Fortran BLAS/LAPACK wrappers still follow the f2c/g77 calling
+convention, while flang uses a different ABI:
+
+1. Fortran subroutines are emitted as returning void, not int. NumPy
+   declared them as returning fortran_int / CBLAS_INT, so wasm-ld
+   reports "function signature mismatch" (i32 vs void) for symbols
+   such as dgeqrf_, dgelsd_, and xerbla_.
+
+2. Each CHARACTER dummy gets a hidden trailing length argument (int).
+   Calls and prototypes that omit those lengths also fail to link, or
+   would mis-call routines such as dpotrf_, dgesdd_, and dgemm_.
+
+This patch mirrors the approach used in the emscripten-forge SciPy
+recipe (extra CHARACTER length arguments and consistent return types):
+
+- Change Fortran subroutine prototypes from fortran_int to void.
+- Append one int length formal per char* parameter.
+- Pass a length actual of 1 at each corresponding call site.
+- Stop using subroutine return values (use info / return 0 instead).
+- Update python_xerbla to void + srname_len so it matches OpenBLAS.
+
+Apply when building NumPy with -Dblas=openblas against the
+emscripten-forge OpenBLAS package (flang-new). Regenerate with
+fix_flang_fortran_abi.py if NumPy's wrappers change upstream.
+---
+ numpy/_core/src/common/python_xerbla.c   |   6 +-
+ numpy/linalg/lapack_lite/python_xerbla.c |   6 +-
+ numpy/linalg/lapack_litemodule.c         |  40 ++---
+ numpy/linalg/umath_linalg.cpp            | 208 +++++++++++------------
+ 4 files changed, 128 insertions(+), 132 deletions(-)
+
+diff --git a/numpy/_core/src/common/python_xerbla.c b/numpy/_core/src/common/python_xerbla.c
+index 71a4c81..13aab59 100644
+--- a/numpy/_core/src/common/python_xerbla.c
++++ b/numpy/_core/src/common/python_xerbla.c
+@@ -21,7 +21,7 @@
+   info: Number of the invalid parameter.
+ */
+ 
+-CBLAS_INT BLAS_FUNC(xerbla)(char *srname, CBLAS_INT *info)
++void BLAS_FUNC(xerbla)(char *srname, CBLAS_INT *info, int srname_len)
+ {
+         static const char format[] = "On entry to %.*s" \
+                 " parameter number %d had an illegal value";
+@@ -30,7 +30,7 @@ CBLAS_INT BLAS_FUNC(xerbla)(char *srname, CBLAS_INT *info)
+         int len = 0; /* length of subroutine name*/
+         PyGILState_STATE save;
+ 
+-        while( len<6 && srname[len]!='\0' )
++        while( len<6 && len<srname_len && srname[len]!='\0' )
+                 len++;
+         while( len && srname[len-1]==' ' )
+                 len--;
+@@ -38,6 +38,4 @@ CBLAS_INT BLAS_FUNC(xerbla)(char *srname, CBLAS_INT *info)
+         PyOS_snprintf(buf, sizeof(buf), format, len, srname, (int)*info);
+         PyErr_SetString(PyExc_ValueError, buf);
+         PyGILState_Release(save);
+-
+-        return 0;
+ }
+diff --git a/numpy/linalg/lapack_lite/python_xerbla.c b/numpy/linalg/lapack_lite/python_xerbla.c
+index 71a4c81..13aab59 100644
+--- a/numpy/linalg/lapack_lite/python_xerbla.c
++++ b/numpy/linalg/lapack_lite/python_xerbla.c
+@@ -21,7 +21,7 @@
+   info: Number of the invalid parameter.
+ */
+ 
+-CBLAS_INT BLAS_FUNC(xerbla)(char *srname, CBLAS_INT *info)
++void BLAS_FUNC(xerbla)(char *srname, CBLAS_INT *info, int srname_len)
+ {
+         static const char format[] = "On entry to %.*s" \
+                 " parameter number %d had an illegal value";
+@@ -30,7 +30,7 @@ CBLAS_INT BLAS_FUNC(xerbla)(char *srname, CBLAS_INT *info)
+         int len = 0; /* length of subroutine name*/
+         PyGILState_STATE save;
+ 
+-        while( len<6 && srname[len]!='\0' )
++        while( len<6 && len<srname_len && srname[len]!='\0' )
+                 len++;
+         while( len && srname[len-1]==' ' )
+                 len--;
+@@ -38,6 +38,4 @@ CBLAS_INT BLAS_FUNC(xerbla)(char *srname, CBLAS_INT *info)
+         PyOS_snprintf(buf, sizeof(buf), format, len, srname, (int)*info);
+         PyErr_SetString(PyExc_ValueError, buf);
+         PyGILState_Release(save);
+-
+-        return 0;
+ }
+diff --git a/numpy/linalg/lapack_litemodule.c b/numpy/linalg/lapack_litemodule.c
+index cad5f3f..8b65743 100644
+--- a/numpy/linalg/lapack_litemodule.c
++++ b/numpy/linalg/lapack_litemodule.c
+@@ -38,35 +38,35 @@ typedef struct { float r, i; } f2c_complex;
+ typedef struct { double r, i; } f2c_doublecomplex;
+ /* typedef long int (*L_fp)(); */
+ 
+-extern fortran_int FNAME(dgelsd)(fortran_int *m, fortran_int *n, fortran_int *nrhs,
++extern void FNAME(dgelsd)(fortran_int *m, fortran_int *n, fortran_int *nrhs,
+                           double a[], fortran_int *lda, double b[], fortran_int *ldb,
+                           double s[], double *rcond, fortran_int *rank,
+                           double work[], fortran_int *lwork, fortran_int iwork[], fortran_int *info);
+ 
+-extern fortran_int FNAME(zgelsd)(fortran_int *m, fortran_int *n, fortran_int *nrhs,
++extern void FNAME(zgelsd)(fortran_int *m, fortran_int *n, fortran_int *nrhs,
+                           f2c_doublecomplex a[], fortran_int *lda,
+                           f2c_doublecomplex b[], fortran_int *ldb,
+                           double s[], double *rcond, fortran_int *rank,
+                           f2c_doublecomplex work[], fortran_int *lwork,
+                           double rwork[], fortran_int iwork[], fortran_int *info);
+ 
+-extern fortran_int FNAME(dgeqrf)(fortran_int *m, fortran_int *n, double a[], fortran_int *lda,
++extern void FNAME(dgeqrf)(fortran_int *m, fortran_int *n, double a[], fortran_int *lda,
+                           double tau[], double work[],
+                           fortran_int *lwork, fortran_int *info);
+ 
+-extern fortran_int FNAME(zgeqrf)(fortran_int *m, fortran_int *n, f2c_doublecomplex a[], fortran_int *lda,
++extern void FNAME(zgeqrf)(fortran_int *m, fortran_int *n, f2c_doublecomplex a[], fortran_int *lda,
+                           f2c_doublecomplex tau[], f2c_doublecomplex work[],
+                           fortran_int *lwork, fortran_int *info);
+ 
+-extern fortran_int FNAME(dorgqr)(fortran_int *m, fortran_int *n, fortran_int *k, double a[], fortran_int *lda,
++extern void FNAME(dorgqr)(fortran_int *m, fortran_int *n, fortran_int *k, double a[], fortran_int *lda,
+                           double tau[], double work[],
+                           fortran_int *lwork, fortran_int *info);
+ 
+-extern fortran_int FNAME(zungqr)(fortran_int *m, fortran_int *n, fortran_int *k, f2c_doublecomplex a[],
++extern void FNAME(zungqr)(fortran_int *m, fortran_int *n, fortran_int *k, f2c_doublecomplex a[],
+                           fortran_int *lda, f2c_doublecomplex tau[],
+                           f2c_doublecomplex work[], fortran_int *lwork, fortran_int *info);
+ 
+-extern fortran_int FNAME(xerbla)(char *srname, fortran_int *info);
++extern void FNAME(xerbla)(char *srname, fortran_int *info, int);
+ 
+ static PyObject *LapackError;
+ 
+@@ -149,10 +149,10 @@ lapack_lite_dgelsd(PyObject *NPY_UNUSED(self), PyObject *args)
+     TRY(check_object(iwork,NPY_INT64,"iwork","NPY_INT64","dgelsd"));
+ #endif
+ 
+-    lapack_lite_status =
+-            FNAME(dgelsd)(&m,&n,&nrhs,DDATA(a),&lda,DDATA(b),&ldb,
++    FNAME(dgelsd)(&m,&n,&nrhs,DDATA(a),&lda,DDATA(b),&ldb,
+                           DDATA(s),&rcond,&rank,DDATA(work),&lwork,
+                           IDATA(iwork),&info);
++        lapack_lite_status = info;
+     if (PyErr_Occurred()) {
+         return NULL;
+     }
+@@ -185,9 +185,9 @@ lapack_lite_dgeqrf(PyObject *NPY_UNUSED(self), PyObject *args)
+         TRY(check_object(tau,NPY_DOUBLE,"tau","NPY_DOUBLE","dgeqrf"));
+         TRY(check_object(work,NPY_DOUBLE,"work","NPY_DOUBLE","dgeqrf"));
+ 
+-        lapack_lite_status =
+-                FNAME(dgeqrf)(&m, &n, DDATA(a), &lda, DDATA(tau),
++        FNAME(dgeqrf)(&m, &n, DDATA(a), &lda, DDATA(tau),
+                               DDATA(work), &lwork, &info);
++        lapack_lite_status = info;
+         if (PyErr_Occurred()) {
+             return NULL;
+         }
+@@ -217,9 +217,9 @@ lapack_lite_dorgqr(PyObject *NPY_UNUSED(self), PyObject *args)
+         TRY(check_object(a,NPY_DOUBLE,"a","NPY_DOUBLE","dorgqr"));
+         TRY(check_object(tau,NPY_DOUBLE,"tau","NPY_DOUBLE","dorgqr"));
+         TRY(check_object(work,NPY_DOUBLE,"work","NPY_DOUBLE","dorgqr"));
+-        lapack_lite_status =
+-            FNAME(dorgqr)(&m, &n, &k, DDATA(a), &lda, DDATA(tau), DDATA(work),
++        FNAME(dorgqr)(&m, &n, &k, DDATA(a), &lda, DDATA(tau), DDATA(work),
+                           &lwork, &info);
++        lapack_lite_status = info;
+         if (PyErr_Occurred()) {
+             return NULL;
+         }
+@@ -266,9 +266,9 @@ lapack_lite_zgelsd(PyObject *NPY_UNUSED(self), PyObject *args)
+     TRY(check_object(iwork,NPY_INT64,"iwork","NPY_INT64","zgelsd"));
+ #endif
+ 
+-    lapack_lite_status =
+-        FNAME(zgelsd)(&m,&n,&nrhs,ZDATA(a),&lda,ZDATA(b),&ldb,DDATA(s),&rcond,
++    FNAME(zgelsd)(&m,&n,&nrhs,ZDATA(a),&lda,ZDATA(b),&ldb,DDATA(s),&rcond,
+                       &rank,ZDATA(work),&lwork,DDATA(rwork),IDATA(iwork),&info);
++        lapack_lite_status = info;
+     if (PyErr_Occurred()) {
+         return NULL;
+     }
+@@ -301,9 +301,9 @@ lapack_lite_zgeqrf(PyObject *NPY_UNUSED(self), PyObject *args)
+         TRY(check_object(tau,NPY_CDOUBLE,"tau","NPY_CDOUBLE","zgeqrf"));
+         TRY(check_object(work,NPY_CDOUBLE,"work","NPY_CDOUBLE","zgeqrf"));
+ 
+-        lapack_lite_status =
+-            FNAME(zgeqrf)(&m, &n, ZDATA(a), &lda, ZDATA(tau), ZDATA(work),
++        FNAME(zgeqrf)(&m, &n, ZDATA(a), &lda, ZDATA(tau), ZDATA(work),
+                           &lwork, &info);
++        lapack_lite_status = info;
+         if (PyErr_Occurred()) {
+             return NULL;
+         }
+@@ -334,9 +334,9 @@ lapack_lite_zungqr(PyObject *NPY_UNUSED(self), PyObject *args)
+         TRY(check_object(work,NPY_CDOUBLE,"work","NPY_CDOUBLE","zungqr"));
+ 
+ 
+-        lapack_lite_status =
+-            FNAME(zungqr)(&m, &n, &k, ZDATA(a), &lda, ZDATA(tau), ZDATA(work),
++        FNAME(zungqr)(&m, &n, &k, ZDATA(a), &lda, ZDATA(tau), ZDATA(work),
+                           &lwork, &info);
++        lapack_lite_status = info;
+         if (PyErr_Occurred()) {
+             return NULL;
+         }
+@@ -354,7 +354,7 @@ lapack_lite_xerbla(PyObject *NPY_UNUSED(self), PyObject *args)
+ 
+     NPY_BEGIN_THREADS_DEF;
+     NPY_BEGIN_THREADS;
+-    FNAME(xerbla)("test", &info);
++    FNAME(xerbla)("test", &info, 1);
+     NPY_END_THREADS;
+ 
+     if (PyErr_Occurred()) {
+diff --git a/numpy/linalg/umath_linalg.cpp b/numpy/linalg/umath_linalg.cpp
+index cf2ec2d..3d9efdf 100644
+--- a/numpy/linalg/umath_linalg.cpp
++++ b/numpy/linalg/umath_linalg.cpp
+@@ -95,19 +95,19 @@ typedef double            fortran_doublereal;
+ typedef f2c_complex       fortran_complex;
+ typedef f2c_doublecomplex fortran_doublecomplex;
+ 
+-extern "C" fortran_int
++extern "C" void
+ FNAME(sgeev)(char *jobvl, char *jobvr, fortran_int *n,
+              float a[], fortran_int *lda, float wr[], float wi[],
+              float vl[], fortran_int *ldvl, float vr[], fortran_int *ldvr,
+              float work[], fortran_int lwork[],
+-             fortran_int *info);
+-extern "C" fortran_int
++             fortran_int *info, int, int);
++extern "C" void
+ FNAME(dgeev)(char *jobvl, char *jobvr, fortran_int *n,
+              double a[], fortran_int *lda, double wr[], double wi[],
+              double vl[], fortran_int *ldvl, double vr[], fortran_int *ldvr,
+              double work[], fortran_int lwork[],
+-             fortran_int *info);
+-extern "C" fortran_int
++             fortran_int *info, int, int);
++extern "C" void
+ FNAME(cgeev)(char *jobvl, char *jobvr, fortran_int *n,
+              f2c_complex a[], fortran_int *lda,
+              f2c_complex w[],
+@@ -115,8 +115,8 @@ FNAME(cgeev)(char *jobvl, char *jobvr, fortran_int *n,
+              f2c_complex vr[], fortran_int *ldvr,
+              f2c_complex work[], fortran_int *lwork,
+              float rwork[],
+-             fortran_int *info);
+-extern "C" fortran_int
++             fortran_int *info, int, int);
++extern "C" void
+ FNAME(zgeev)(char *jobvl, char *jobvr, fortran_int *n,
+              f2c_doublecomplex a[], fortran_int *lda,
+              f2c_doublecomplex w[],
+@@ -124,46 +124,46 @@ FNAME(zgeev)(char *jobvl, char *jobvr, fortran_int *n,
+              f2c_doublecomplex vr[], fortran_int *ldvr,
+              f2c_doublecomplex work[], fortran_int *lwork,
+              double rwork[],
+-             fortran_int *info);
++             fortran_int *info, int, int);
+ 
+-extern "C" fortran_int
++extern "C" void
+ FNAME(ssyevd)(char *jobz, char *uplo, fortran_int *n,
+               float a[], fortran_int *lda, float w[], float work[],
+               fortran_int *lwork, fortran_int iwork[], fortran_int *liwork,
+-              fortran_int *info);
+-extern "C" fortran_int
++              fortran_int *info, int, int);
++extern "C" void
+ FNAME(dsyevd)(char *jobz, char *uplo, fortran_int *n,
+               double a[], fortran_int *lda, double w[], double work[],
+               fortran_int *lwork, fortran_int iwork[], fortran_int *liwork,
+-              fortran_int *info);
+-extern "C" fortran_int
++              fortran_int *info, int, int);
++extern "C" void
+ FNAME(cheevd)(char *jobz, char *uplo, fortran_int *n,
+               f2c_complex a[], fortran_int *lda,
+               float w[], f2c_complex work[],
+               fortran_int *lwork, float rwork[], fortran_int *lrwork, fortran_int iwork[],
+               fortran_int *liwork,
+-              fortran_int *info);
+-extern "C" fortran_int
++              fortran_int *info, int, int);
++extern "C" void
+ FNAME(zheevd)(char *jobz, char *uplo, fortran_int *n,
+               f2c_doublecomplex a[], fortran_int *lda,
+               double w[], f2c_doublecomplex work[],
+               fortran_int *lwork, double rwork[], fortran_int *lrwork, fortran_int iwork[],
+               fortran_int *liwork,
+-              fortran_int *info);
++              fortran_int *info, int, int);
+ 
+-extern "C" fortran_int
++extern "C" void
+ FNAME(sgelsd)(fortran_int *m, fortran_int *n, fortran_int *nrhs,
+               float a[], fortran_int *lda, float b[], fortran_int *ldb,
+               float s[], float *rcond, fortran_int *rank,
+               float work[], fortran_int *lwork, fortran_int iwork[],
+               fortran_int *info);
+-extern "C" fortran_int
++extern "C" void
+ FNAME(dgelsd)(fortran_int *m, fortran_int *n, fortran_int *nrhs,
+               double a[], fortran_int *lda, double b[], fortran_int *ldb,
+               double s[], double *rcond, fortran_int *rank,
+               double work[], fortran_int *lwork, fortran_int iwork[],
+               fortran_int *info);
+-extern "C" fortran_int
++extern "C" void
+ FNAME(cgelsd)(fortran_int *m, fortran_int *n, fortran_int *nrhs,
+               f2c_complex a[], fortran_int *lda,
+               f2c_complex b[], fortran_int *ldb,
+@@ -171,7 +171,7 @@ FNAME(cgelsd)(fortran_int *m, fortran_int *n, fortran_int *nrhs,
+               f2c_complex work[], fortran_int *lwork,
+               float rwork[], fortran_int iwork[],
+               fortran_int *info);
+-extern "C" fortran_int
++extern "C" void
+ FNAME(zgelsd)(fortran_int *m, fortran_int *n, fortran_int *nrhs,
+               f2c_doublecomplex a[], fortran_int *lda,
+               f2c_doublecomplex b[], fortran_int *ldb,
+@@ -180,163 +180,163 @@ FNAME(zgelsd)(fortran_int *m, fortran_int *n, fortran_int *nrhs,
+               double rwork[], fortran_int iwork[],
+               fortran_int *info);
+ 
+-extern "C" fortran_int
++extern "C" void
+ FNAME(dgeqrf)(fortran_int *m, fortran_int *n, double a[], fortran_int *lda,
+               double tau[], double work[],
+               fortran_int *lwork, fortran_int *info);
+-extern "C" fortran_int
++extern "C" void
+ FNAME(zgeqrf)(fortran_int *m, fortran_int *n, f2c_doublecomplex a[], fortran_int *lda,
+               f2c_doublecomplex tau[], f2c_doublecomplex work[],
+               fortran_int *lwork, fortran_int *info);
+ 
+-extern "C" fortran_int
++extern "C" void
+ FNAME(dorgqr)(fortran_int *m, fortran_int *n, fortran_int *k, double a[], fortran_int *lda,
+               double tau[], double work[],
+               fortran_int *lwork, fortran_int *info);
+-extern "C" fortran_int
++extern "C" void
+ FNAME(zungqr)(fortran_int *m, fortran_int *n, fortran_int *k, f2c_doublecomplex a[],
+               fortran_int *lda, f2c_doublecomplex tau[],
+               f2c_doublecomplex work[], fortran_int *lwork, fortran_int *info);
+ 
+-extern "C" fortran_int
++extern "C" void
+ FNAME(sgesv)(fortran_int *n, fortran_int *nrhs,
+              float a[], fortran_int *lda,
+              fortran_int ipiv[],
+              float b[], fortran_int *ldb,
+              fortran_int *info);
+-extern "C" fortran_int
++extern "C" void
+ FNAME(dgesv)(fortran_int *n, fortran_int *nrhs,
+              double a[], fortran_int *lda,
+              fortran_int ipiv[],
+              double b[], fortran_int *ldb,
+              fortran_int *info);
+-extern "C" fortran_int
++extern "C" void
+ FNAME(cgesv)(fortran_int *n, fortran_int *nrhs,
+              f2c_complex a[], fortran_int *lda,
+              fortran_int ipiv[],
+              f2c_complex b[], fortran_int *ldb,
+              fortran_int *info);
+-extern "C" fortran_int
++extern "C" void
+ FNAME(zgesv)(fortran_int *n, fortran_int *nrhs,
+              f2c_doublecomplex a[], fortran_int *lda,
+              fortran_int ipiv[],
+              f2c_doublecomplex b[], fortran_int *ldb,
+              fortran_int *info);
+ 
+-extern "C" fortran_int
++extern "C" void
+ FNAME(sgetrf)(fortran_int *m, fortran_int *n,
+               float a[], fortran_int *lda,
+               fortran_int ipiv[],
+               fortran_int *info);
+-extern "C" fortran_int
++extern "C" void
+ FNAME(dgetrf)(fortran_int *m, fortran_int *n,
+               double a[], fortran_int *lda,
+               fortran_int ipiv[],
+               fortran_int *info);
+-extern "C" fortran_int
++extern "C" void
+ FNAME(cgetrf)(fortran_int *m, fortran_int *n,
+               f2c_complex a[], fortran_int *lda,
+               fortran_int ipiv[],
+               fortran_int *info);
+-extern "C" fortran_int
++extern "C" void
+ FNAME(zgetrf)(fortran_int *m, fortran_int *n,
+               f2c_doublecomplex a[], fortran_int *lda,
+               fortran_int ipiv[],
+               fortran_int *info);
+ 
+-extern "C" fortran_int
++extern "C" void
+ FNAME(spotrf)(char *uplo, fortran_int *n,
+               float a[], fortran_int *lda,
+-              fortran_int *info);
+-extern "C" fortran_int
++              fortran_int *info, int);
++extern "C" void
+ FNAME(dpotrf)(char *uplo, fortran_int *n,
+               double a[], fortran_int *lda,
+-              fortran_int *info);
+-extern "C" fortran_int
++              fortran_int *info, int);
++extern "C" void
+ FNAME(cpotrf)(char *uplo, fortran_int *n,
+               f2c_complex a[], fortran_int *lda,
+-              fortran_int *info);
+-extern "C" fortran_int
++              fortran_int *info, int);
++extern "C" void
+ FNAME(zpotrf)(char *uplo, fortran_int *n,
+               f2c_doublecomplex a[], fortran_int *lda,
+-              fortran_int *info);
++              fortran_int *info, int);
+ 
+-extern "C" fortran_int
++extern "C" void
+ FNAME(sgesdd)(char *jobz, fortran_int *m, fortran_int *n,
+               float a[], fortran_int *lda, float s[], float u[],
+               fortran_int *ldu, float vt[], fortran_int *ldvt, float work[],
+-              fortran_int *lwork, fortran_int iwork[], fortran_int *info);
+-extern "C" fortran_int
++              fortran_int *lwork, fortran_int iwork[], fortran_int *info, int);
++extern "C" void
+ FNAME(dgesdd)(char *jobz, fortran_int *m, fortran_int *n,
+               double a[], fortran_int *lda, double s[], double u[],
+               fortran_int *ldu, double vt[], fortran_int *ldvt, double work[],
+-              fortran_int *lwork, fortran_int iwork[], fortran_int *info);
+-extern "C" fortran_int
++              fortran_int *lwork, fortran_int iwork[], fortran_int *info, int);
++extern "C" void
+ FNAME(cgesdd)(char *jobz, fortran_int *m, fortran_int *n,
+               f2c_complex a[], fortran_int *lda,
+               float s[], f2c_complex u[], fortran_int *ldu,
+               f2c_complex vt[], fortran_int *ldvt,
+               f2c_complex work[], fortran_int *lwork,
+-              float rwork[], fortran_int iwork[], fortran_int *info);
+-extern "C" fortran_int
++              float rwork[], fortran_int iwork[], fortran_int *info, int);
++extern "C" void
+ FNAME(zgesdd)(char *jobz, fortran_int *m, fortran_int *n,
+               f2c_doublecomplex a[], fortran_int *lda,
+               double s[], f2c_doublecomplex u[], fortran_int *ldu,
+               f2c_doublecomplex vt[], fortran_int *ldvt,
+               f2c_doublecomplex work[], fortran_int *lwork,
+-              double rwork[], fortran_int iwork[], fortran_int *info);
++              double rwork[], fortran_int iwork[], fortran_int *info, int);
+ 
+-extern "C" fortran_int
++extern "C" void
+ FNAME(spotrs)(char *uplo, fortran_int *n, fortran_int *nrhs,
+               float a[], fortran_int *lda,
+               float b[], fortran_int *ldb,
+-              fortran_int *info);
+-extern "C" fortran_int
++              fortran_int *info, int);
++extern "C" void
+ FNAME(dpotrs)(char *uplo, fortran_int *n, fortran_int *nrhs,
+               double a[], fortran_int *lda,
+               double b[], fortran_int *ldb,
+-              fortran_int *info);
+-extern "C" fortran_int
++              fortran_int *info, int);
++extern "C" void
+ FNAME(cpotrs)(char *uplo, fortran_int *n, fortran_int *nrhs,
+               f2c_complex a[], fortran_int *lda,
+               f2c_complex b[], fortran_int *ldb,
+-              fortran_int *info);
+-extern "C" fortran_int
++              fortran_int *info, int);
++extern "C" void
+ FNAME(zpotrs)(char *uplo, fortran_int *n, fortran_int *nrhs,
+               f2c_doublecomplex a[], fortran_int *lda,
+               f2c_doublecomplex b[], fortran_int *ldb,
+-              fortran_int *info);
++              fortran_int *info, int);
+ 
+-extern "C" fortran_int
++extern "C" void
+ FNAME(spotri)(char *uplo, fortran_int *n,
+               float a[], fortran_int *lda,
+-              fortran_int *info);
+-extern "C" fortran_int
++              fortran_int *info, int);
++extern "C" void
+ FNAME(dpotri)(char *uplo, fortran_int *n,
+               double a[], fortran_int *lda,
+-              fortran_int *info);
+-extern "C" fortran_int
++              fortran_int *info, int);
++extern "C" void
+ FNAME(cpotri)(char *uplo, fortran_int *n,
+               f2c_complex a[], fortran_int *lda,
+-              fortran_int *info);
+-extern "C" fortran_int
++              fortran_int *info, int);
++extern "C" void
+ FNAME(zpotri)(char *uplo, fortran_int *n,
+               f2c_doublecomplex a[], fortran_int *lda,
+-              fortran_int *info);
++              fortran_int *info, int);
+ 
+-extern "C" fortran_int
++extern "C" void
+ FNAME(scopy)(fortran_int *n,
+              float *sx, fortran_int *incx,
+              float *sy, fortran_int *incy);
+-extern "C" fortran_int
++extern "C" void
+ FNAME(dcopy)(fortran_int *n,
+              double *sx, fortran_int *incx,
+              double *sy, fortran_int *incy);
+-extern "C" fortran_int
++extern "C" void
+ FNAME(ccopy)(fortran_int *n,
+              f2c_complex *sx, fortran_int *incx,
+              f2c_complex *sy, fortran_int *incy);
+-extern "C" fortran_int
++extern "C" void
+ FNAME(zcopy)(fortran_int *n,
+              f2c_doublecomplex *sx, fortran_int *incx,
+              f2c_doublecomplex *sy, fortran_int *incy);
+@@ -366,38 +366,38 @@ FNAME(zdotc)(f2c_doublecomplex *ret, fortran_int *n,
+              f2c_doublecomplex *sx, fortran_int *incx,
+              f2c_doublecomplex *sy, fortran_int *incy);
+ 
+-extern "C" fortran_int
++extern "C" void
+ FNAME(sgemm)(char *transa, char *transb,
+              fortran_int *m, fortran_int *n, fortran_int *k,
+              float *alpha,
+              float *a, fortran_int *lda,
+              float *b, fortran_int *ldb,
+              float *beta,
+-             float *c, fortran_int *ldc);
+-extern "C" fortran_int
++             float *c, fortran_int *ldc, int, int);
++extern "C" void
+ FNAME(dgemm)(char *transa, char *transb,
+              fortran_int *m, fortran_int *n, fortran_int *k,
+              double *alpha,
+              double *a, fortran_int *lda,
+              double *b, fortran_int *ldb,
+              double *beta,
+-             double *c, fortran_int *ldc);
+-extern "C" fortran_int
++             double *c, fortran_int *ldc, int, int);
++extern "C" void
+ FNAME(cgemm)(char *transa, char *transb,
+              fortran_int *m, fortran_int *n, fortran_int *k,
+              f2c_complex *alpha,
+              f2c_complex *a, fortran_int *lda,
+              f2c_complex *b, fortran_int *ldb,
+              f2c_complex *beta,
+-             f2c_complex *c, fortran_int *ldc);
+-extern "C" fortran_int
++             f2c_complex *c, fortran_int *ldc, int, int);
++extern "C" void
+ FNAME(zgemm)(char *transa, char *transb,
+              fortran_int *m, fortran_int *n, fortran_int *k,
+              f2c_doublecomplex *alpha,
+              f2c_doublecomplex *a, fortran_int *lda,
+              f2c_doublecomplex *b, fortran_int *ldb,
+              f2c_doublecomplex *beta,
+-             f2c_doublecomplex *c, fortran_int *ldc);
++             f2c_doublecomplex *c, fortran_int *ldc, int, int);
+ 
+ 
+ #define LAPACK_T(FUNC)                                          \
+@@ -794,40 +794,40 @@ update_pointers(npy_uint8** bases, ptrdiff_t* offsets, size_t count)
+  */
+ static fortran_int copy(fortran_int *n,
+         float *sx, fortran_int *incx,
+-        float *sy, fortran_int *incy) { return FNAME(scopy)(n, sx, incx,
+-            sy, incy);
++        float *sy, fortran_int *incy) { FNAME(scopy)(n, sx, incx,
++            sy, incy); return 0;
+ }
+ static fortran_int copy(fortran_int *n,
+         double *sx, fortran_int *incx,
+-        double *sy, fortran_int *incy) { return FNAME(dcopy)(n, sx, incx,
+-            sy, incy);
++        double *sy, fortran_int *incy) { FNAME(dcopy)(n, sx, incx,
++            sy, incy); return 0;
+ }
+ static fortran_int copy(fortran_int *n,
+         f2c_complex *sx, fortran_int *incx,
+-        f2c_complex *sy, fortran_int *incy) { return FNAME(ccopy)(n, sx, incx,
+-            sy, incy);
++        f2c_complex *sy, fortran_int *incy) { FNAME(ccopy)(n, sx, incx,
++            sy, incy); return 0;
+ }
+ static fortran_int copy(fortran_int *n,
+         f2c_doublecomplex *sx, fortran_int *incx,
+-        f2c_doublecomplex *sy, fortran_int *incy) { return FNAME(zcopy)(n, sx, incx,
+-            sy, incy);
++        f2c_doublecomplex *sy, fortran_int *incy) { FNAME(zcopy)(n, sx, incx,
++            sy, incy); return 0;
+ }
+ 
+ static fortran_int getrf(fortran_int *m, fortran_int *n, float a[], fortran_int
+ *lda, fortran_int ipiv[], fortran_int *info) {
+- return LAPACK(sgetrf)(m, n, a, lda, ipiv, info);
++ LAPACK(sgetrf)(m, n, a, lda, ipiv, info); return 0;
+ }
+ static fortran_int getrf(fortran_int *m, fortran_int *n, double a[], fortran_int
+ *lda, fortran_int ipiv[], fortran_int *info) {
+- return LAPACK(dgetrf)(m, n, a, lda, ipiv, info);
++ LAPACK(dgetrf)(m, n, a, lda, ipiv, info); return 0;
+ }
+ static fortran_int getrf(fortran_int *m, fortran_int *n, f2c_complex a[], fortran_int
+ *lda, fortran_int ipiv[], fortran_int *info) {
+- return LAPACK(cgetrf)(m, n, a, lda, ipiv, info);
++ LAPACK(cgetrf)(m, n, a, lda, ipiv, info); return 0;
+ }
+ static fortran_int getrf(fortran_int *m, fortran_int *n, f2c_doublecomplex a[], fortran_int
+ *lda, fortran_int ipiv[], fortran_int *info) {
+- return LAPACK(zgetrf)(m, n, a, lda, ipiv, info);
++ LAPACK(zgetrf)(m, n, a, lda, ipiv, info); return 0;
+ }
+ 
+ /*
+@@ -1294,7 +1294,7 @@ call_evd(EIGH_PARAMS_t<npy_float> *params)
+                           params->A, &params->LDA, params->W,
+                           params->WORK, &params->LWORK,
+                           params->IWORK, &params->LIWORK,
+-                          &rv);
++                          &rv, 1, 1);
+     UNLOCK_LAPACK_LITE;
+     return rv;
+ }
+@@ -1307,7 +1307,7 @@ call_evd(EIGH_PARAMS_t<npy_double> *params)
+                           params->A, &params->LDA, params->W,
+                           params->WORK, &params->LWORK,
+                           params->IWORK, &params->LIWORK,
+-                          &rv);
++                          &rv, 1, 1);
+     UNLOCK_LAPACK_LITE;
+     return rv;
+ }
+@@ -1404,7 +1404,7 @@ call_evd(EIGH_PARAMS_t<npy_cfloat> *params)
+                           (fortran_type_t<npy_cfloat>*)params->WORK, &params->LWORK,
+                           params->RWORK, &params->LRWORK,
+                           params->IWORK, &params->LIWORK,
+-                          &rv);
++                          &rv, 1, 1);
+     UNLOCK_LAPACK_LITE;
+     return rv;
+ }
+@@ -1419,7 +1419,7 @@ call_evd(EIGH_PARAMS_t<npy_cdouble> *params)
+                           (fortran_type_t<npy_cdouble>*)params->WORK, &params->LWORK,
+                           params->RWORK, &params->LRWORK,
+                           params->IWORK, &params->LIWORK,
+-                          &rv);
++                          &rv, 1, 1);
+     UNLOCK_LAPACK_LITE;
+     return rv;
+ }
+@@ -1924,7 +1924,7 @@ call_potrf(POTR_PARAMS_t<fortran_real> *params)
+     LOCK_LAPACK_LITE;
+     LAPACK(spotrf)(&params->UPLO,
+                           &params->N, params->A, &params->LDA,
+-                          &rv);
++                          &rv, 1);
+     UNLOCK_LAPACK_LITE;
+     return rv;
+ }
+@@ -1936,7 +1936,7 @@ call_potrf(POTR_PARAMS_t<fortran_doublereal> *params)
+     LOCK_LAPACK_LITE;
+     LAPACK(dpotrf)(&params->UPLO,
+                           &params->N, params->A, &params->LDA,
+-                          &rv);
++                          &rv, 1);
+     UNLOCK_LAPACK_LITE;
+     return rv;
+ }
+@@ -1948,7 +1948,7 @@ call_potrf(POTR_PARAMS_t<fortran_complex> *params)
+     LOCK_LAPACK_LITE;
+     LAPACK(cpotrf)(&params->UPLO,
+                           &params->N, params->A, &params->LDA,
+-                          &rv);
++                          &rv, 1);
+     UNLOCK_LAPACK_LITE;
+     return rv;
+ }
+@@ -1960,7 +1960,7 @@ call_potrf(POTR_PARAMS_t<fortran_doublecomplex> *params)
+     LOCK_LAPACK_LITE;
+     LAPACK(zpotrf)(&params->UPLO,
+                           &params->N, params->A, &params->LDA,
+-                          &rv);
++                          &rv, 1);
+     UNLOCK_LAPACK_LITE;
+     return rv;
+ }
+@@ -2141,7 +2141,7 @@ call_geev(GEEV_PARAMS_t<float>* params)
+                           params->VLR, &params->LDVL,
+                           params->VRR, &params->LDVR,
+                           params->WORK, &params->LWORK,
+-                          &rv);
++                          &rv, 1, 1);
+     UNLOCK_LAPACK_LITE;
+     return rv;
+ }
+@@ -2157,7 +2157,7 @@ call_geev(GEEV_PARAMS_t<double>* params)
+                           params->VLR, &params->LDVL,
+                           params->VRR, &params->LDVR,
+                           params->WORK, &params->LWORK,
+-                          &rv);
++                          &rv, 1, 1);
+     UNLOCK_LAPACK_LITE;
+     return rv;
+ }
+@@ -2362,7 +2362,7 @@ call_geev(GEEV_PARAMS_t<fortran_complex>* params)
+                           params->VR, &params->LDVR,
+                           params->WORK, &params->LWORK,
+                           params->WR, /* actually RWORK */
+-                          &rv);
++                          &rv, 1, 1);
+     UNLOCK_LAPACK_LITE;
+     return rv;
+ }
+@@ -2381,7 +2381,7 @@ call_geev(GEEV_PARAMS_t<fortran_doublecomplex>* params)
+                           params->VR, &params->LDVR,
+                           params->WORK, &params->LWORK,
+                           params->WR, /* actually RWORK */
+-                          &rv);
++                          &rv, 1, 1);
+     UNLOCK_LAPACK_LITE;
+     return rv;
+ }
+@@ -2716,7 +2716,7 @@ call_gesdd(GESDD_PARAMS_t<fortran_real> *params)
+                           params->VT, &params->LDVT,
+                           params->WORK, &params->LWORK,
+                           (fortran_int*)params->IWORK,
+-                          &rv);
++                          &rv, 1);
+     UNLOCK_LAPACK_LITE;
+     return rv;
+ }
+@@ -2732,7 +2732,7 @@ call_gesdd(GESDD_PARAMS_t<fortran_doublereal> *params)
+                           params->VT, &params->LDVT,
+                           params->WORK, &params->LWORK,
+                           (fortran_int*)params->IWORK,
+-                          &rv);
++                          &rv, 1);
+     UNLOCK_LAPACK_LITE;
+     return rv;
+ }
+@@ -2852,7 +2852,7 @@ call_gesdd(GESDD_PARAMS_t<fortran_complex> *params)
+                           params->WORK, &params->LWORK,
+                           params->RWORK,
+                           params->IWORK,
+-                          &rv);
++                          &rv, 1);
+     LOCK_LAPACK_LITE;
+     return rv;
+ }
+@@ -2869,7 +2869,7 @@ call_gesdd(GESDD_PARAMS_t<fortran_doublecomplex> *params)
+                           params->WORK, &params->LWORK,
+                           params->RWORK,
+                           params->IWORK,
+-                          &rv);
++                          &rv, 1);
+     UNLOCK_LAPACK_LITE;
+     return rv;
+ }
+-- 
+2.55.0
+
diff --git a/recipes/recipes_emscripten/numpy/recipe.yaml b/recipes/recipes_emscripten/numpy/recipe.yaml
index 4a3e146dc6e..59462b22c4a 100644
--- a/recipes/recipes_emscripten/numpy/recipe.yaml
+++ b/recipes/recipes_emscripten/numpy/recipe.yaml
@@ -10,6 +10,8 @@ package:
 source:
   url: https://github.com/numpy/numpy/releases/download/v${{ version }}/numpy-${{ version }}.tar.gz
   sha256: a48a113e6afea91f5608793bafa7ef2ad481fefbda87ec5069f483de61cb9fa3
+  patches:
+  - patches/0001-Match-flang-OpenBLAS-Fortran-ABI-on-Emscripten-wasm32.patch
 build:
   number: 1
 

From d27d8ac05a9dbd7969c83fc3eee3ee3011ce2090 Mon Sep 17 00:00:00 2001
From: Julien Jerphanion <git@jjerphan.xyz>
Date: Mon, 10 Aug 2026 13:53:36 +0200
Subject: [PATCH 5/8] Published to `emscripten-forge-4x-experimental`

Signed-off-by: Julien Jerphanion <git@jjerphan.xyz>

Co-authored-by: Isabel Paredes <isabel.paredes@quantstack.net>
---
 recipes/recipes_emscripten/numpy/recipe.yaml | 1 +
 1 file changed, 1 insertion(+)

diff --git a/recipes/recipes_emscripten/numpy/recipe.yaml b/recipes/recipes_emscripten/numpy/recipe.yaml
index 59462b22c4a..5b7ae968c46 100644
--- a/recipes/recipes_emscripten/numpy/recipe.yaml
+++ b/recipes/recipes_emscripten/numpy/recipe.yaml
@@ -64,3 +64,4 @@ about:
 extra:
   recipe-maintainers:
   - DerThorsten
+  channel: emscripten-forge-4x-experimental
\ No newline at end of file

From 95f12e5264286addab8cbadf6dea8c9babd9eec4 Mon Sep 17 00:00:00 2001
From: Julien Jerphanion <git@jjerphan.xyz>
Date: Mon, 10 Aug 2026 14:13:32 +0200
Subject: [PATCH 6/8] Reuse OpenBLAS pkg-config and only alias scipy-openblas

Drop the handwritten openblas.pc rewrite now that openblas ships a
relocatable .pc; keep a build-local scipy-openblas alias so Meson
skips its OpenBLAS symbol probes under wasm-ld.

Signed-off-by: Julien Jerphanion <git@jjerphan.xyz>
---
 recipes/recipes_emscripten/numpy/build.sh | 43 ++++++++---------------
 1 file changed, 15 insertions(+), 28 deletions(-)

diff --git a/recipes/recipes_emscripten/numpy/build.sh b/recipes/recipes_emscripten/numpy/build.sh
index 095d5067bdf..6acdcb31041 100644
--- a/recipes/recipes_emscripten/numpy/build.sh
+++ b/recipes/recipes_emscripten/numpy/build.sh
@@ -6,33 +6,21 @@ echo "PYTHON"
 
 rm -r -f branding
 
-# OpenBLAS must be visible to Meson via pkg-config during the cross build.
-# Channel packages may still embed the original build-machine placeholder
-# paths in openblas.pc; write corrected .pc files into a build-local
-# pkgconfig dir (not $PREFIX — that would ship them in the numpy package).
-#
-# Also install a scipy-openblas.pc alias. NumPy prefers that name and looks
-# it up with plain pkg-config (same pattern as SciPy). That bypasses Meson's
-# packages['openblas'] factory, whose void dgemm_()/cblas_dgemm() symbol
-# probes fail under wasm-ld signature matching against flang-built OpenBLAS.
+# Prefer the relocatable openblas.pc shipped by the openblas package.
+export PKG_CONFIG_PATH="${PREFIX}/lib/pkgconfig${PKG_CONFIG_PATH:+:${PKG_CONFIG_PATH}}"
+
+# NumPy tries dependency('scipy-openblas', method: 'pkg-config') before
+# dependency('openblas'). That name is not registered in Meson's BLAS
+# factory, so it avoids wasm-ld-breaking void dgemm_() symbol probes.
+# OpenBLAS only ships openblas.pc; provide a build-local alias derived
+# from it (rewrite prefix to $PREFIX — pcfiledir would be wrong here).
 PKGCONFIG_DIR="${SRC_DIR}/.emscripten-pkgconfig"
 mkdir -p "${PKGCONFIG_DIR}"
-for pc_name in openblas scipy-openblas; do
-  cat > "${PKGCONFIG_DIR}/${pc_name}.pc" <<EOF
-prefix=${PREFIX}
-libdir=\${prefix}/lib
-includedir=\${prefix}/include
-openblas_config=USE_THREAD=0 TARGET=RISCV64_GENERIC
-version=0.3.31
-Name: ${pc_name}
-Description: OpenBLAS is an optimized BLAS library based on GotoBLAS2 1.13 BSD version
-Version: \${version}
-Libs: -L\${libdir} -lopenblas
-Cflags: -I\${includedir}
-EOF
-done
-
-export PKG_CONFIG_PATH="${PKGCONFIG_DIR}${PKG_CONFIG_PATH:+:${PKG_CONFIG_PATH}}"
+sed -e "s|^prefix=.*|prefix=${PREFIX}|" \
+    -e 's/^Name: .*/Name: scipy-openblas/' \
+    "${PREFIX}/lib/pkgconfig/openblas.pc" \
+    > "${PKGCONFIG_DIR}/scipy-openblas.pc"
+export PKG_CONFIG_PATH="${PKGCONFIG_DIR}:${PKG_CONFIG_PATH}"
 
 # Fail early if OpenBLAS is not usable from pkg-config.
 pkg-config --exists --print-errors openblas
@@ -41,13 +29,12 @@ pkg-config --cflags --libs openblas
 test -f "${PREFIX}/include/cblas.h"
 test -f "${PREFIX}/lib/libopenblas.so"
 
-# Point Meson's host pkg-config search at the build-local .pc files (cross
-# builds do not always inherit PKG_CONFIG_PATH the way native builds do).
+# Cross builds do not always inherit PKG_CONFIG_PATH; tell Meson where to look.
 cp "${RECIPE_DIR}/emscripten.meson.cross" "${SRC_DIR}/emscripten.meson.cross"
 cat >> "${SRC_DIR}/emscripten.meson.cross" <<EOF
 
 [built-in options]
-pkg_config_path = ['${PKGCONFIG_DIR}']
+pkg_config_path = ['${PKGCONFIG_DIR}', '${PREFIX}/lib/pkgconfig']
 EOF
 export MESON_CROSS_FILE="${SRC_DIR}/emscripten.meson.cross"
 

From 0529ca6992badd69408aa64d20d78611abef1b7d Mon Sep 17 00:00:00 2001
From: Julien Jerphanion <git@jjerphan.xyz>
Date: Mon, 10 Aug 2026 14:19:46 +0200
Subject: [PATCH 7/8] Move all changes in `numpy-openblas` and revert `numpy`

Signed-off-by: Julien Jerphanion <git@jjerphan.xyz>
---
 .../numpy-openblas/build.sh                   |  59 +++
 .../numpy-openblas/config/LICENSE             | 373 ++++++++++++++++++
 .../numpy-openblas/config/_numpyconfig.h      |  30 ++
 .../numpy-openblas/config/config.h.in         | 119 ++++++
 .../numpy-openblas/emscripten.meson.cross     |  62 +++
 .../fix_flang_fortran_abi.py                  |   0
 ...LAS-Fortran-ABI-on-Emscripten-wasm32.patch |   0
 .../numpy-openblas/recipe.yaml                |  67 ++++
 .../numpy-openblas/test_numpy.py              |  60 +++
 recipes/recipes_emscripten/numpy/build.sh     |  47 +--
 .../numpy/emscripten.meson.cross              |   2 +-
 recipes/recipes_emscripten/numpy/recipe.yaml  |   9 +-
 .../recipes_emscripten/numpy/test_numpy.py    |  61 +--
 13 files changed, 782 insertions(+), 107 deletions(-)
 create mode 100644 recipes/recipes_emscripten/numpy-openblas/build.sh
 create mode 100644 recipes/recipes_emscripten/numpy-openblas/config/LICENSE
 create mode 100644 recipes/recipes_emscripten/numpy-openblas/config/_numpyconfig.h
 create mode 100644 recipes/recipes_emscripten/numpy-openblas/config/config.h.in
 create mode 100644 recipes/recipes_emscripten/numpy-openblas/emscripten.meson.cross
 rename recipes/recipes_emscripten/{numpy => numpy-openblas}/fix_flang_fortran_abi.py (100%)
 rename recipes/recipes_emscripten/{numpy => numpy-openblas}/patches/0001-Match-flang-OpenBLAS-Fortran-ABI-on-Emscripten-wasm32.patch (100%)
 create mode 100644 recipes/recipes_emscripten/numpy-openblas/recipe.yaml
 create mode 100644 recipes/recipes_emscripten/numpy-openblas/test_numpy.py

diff --git a/recipes/recipes_emscripten/numpy-openblas/build.sh b/recipes/recipes_emscripten/numpy-openblas/build.sh
new file mode 100644
index 00000000000..6acdcb31041
--- /dev/null
+++ b/recipes/recipes_emscripten/numpy-openblas/build.sh
@@ -0,0 +1,59 @@
+#!/bin/bash
+
+set -ex
+
+echo "PYTHON"
+
+rm -r -f branding
+
+# Prefer the relocatable openblas.pc shipped by the openblas package.
+export PKG_CONFIG_PATH="${PREFIX}/lib/pkgconfig${PKG_CONFIG_PATH:+:${PKG_CONFIG_PATH}}"
+
+# NumPy tries dependency('scipy-openblas', method: 'pkg-config') before
+# dependency('openblas'). That name is not registered in Meson's BLAS
+# factory, so it avoids wasm-ld-breaking void dgemm_() symbol probes.
+# OpenBLAS only ships openblas.pc; provide a build-local alias derived
+# from it (rewrite prefix to $PREFIX — pcfiledir would be wrong here).
+PKGCONFIG_DIR="${SRC_DIR}/.emscripten-pkgconfig"
+mkdir -p "${PKGCONFIG_DIR}"
+sed -e "s|^prefix=.*|prefix=${PREFIX}|" \
+    -e 's/^Name: .*/Name: scipy-openblas/' \
+    "${PREFIX}/lib/pkgconfig/openblas.pc" \
+    > "${PKGCONFIG_DIR}/scipy-openblas.pc"
+export PKG_CONFIG_PATH="${PKGCONFIG_DIR}:${PKG_CONFIG_PATH}"
+
+# Fail early if OpenBLAS is not usable from pkg-config.
+pkg-config --exists --print-errors openblas
+pkg-config --exists --print-errors scipy-openblas
+pkg-config --cflags --libs openblas
+test -f "${PREFIX}/include/cblas.h"
+test -f "${PREFIX}/lib/libopenblas.so"
+
+# Cross builds do not always inherit PKG_CONFIG_PATH; tell Meson where to look.
+cp "${RECIPE_DIR}/emscripten.meson.cross" "${SRC_DIR}/emscripten.meson.cross"
+cat >> "${SRC_DIR}/emscripten.meson.cross" <<EOF
+
+[built-in options]
+pkg_config_path = ['${PKGCONFIG_DIR}', '${PREFIX}/lib/pkgconfig']
+EOF
+export MESON_CROSS_FILE="${SRC_DIR}/emscripten.meson.cross"
+
+export CFLAGS="$CFLAGS -Wno-return-type -Wno-implicit-function-declaration -msimd128 -fwasm-exceptions -s SUPPORT_LONGJMP"
+export LDFLAGS="$LDFLAGS -sWASM_BIGINT 	-s WASM_BIGINT -fwasm-exceptions -s SUPPORT_LONGJMP"
+
+cp $RECIPE_DIR/config/config.h.in  numpy/_core/config.h.in
+
+# otherwise "cython" is not properly executable
+echo "add shebang to cython file"
+sed -i '1i#!/usr/bin/env python' $BUILD_PREFIX/bin/cython
+
+# replace -fexceptions with -fwasm-exceptions in numpy/_core
+sed -i 's/-fexceptions/-fwasm-exceptions/g' numpy/_core/meson.build
+
+# -Dblas=openblas makes NumPy try scipy-openblas first (see numpy/meson.build).
+# allow-noblas defaults to true; force OpenBLAS to be required.
+${PYTHON} -m pip install . -vvv --no-deps --no-build-isolation \
+    -Csetup-args="-Dblas=openblas" \
+    -Csetup-args="-Dlapack=openblas" \
+    -Csetup-args="-Dallow-noblas=false" \
+    -Csetup-args="--cross-file=$MESON_CROSS_FILE"
diff --git a/recipes/recipes_emscripten/numpy-openblas/config/LICENSE b/recipes/recipes_emscripten/numpy-openblas/config/LICENSE
new file mode 100644
index 00000000000..a612ad9813b
--- /dev/null
+++ b/recipes/recipes_emscripten/numpy-openblas/config/LICENSE
@@ -0,0 +1,373 @@
+Mozilla Public License Version 2.0
+==================================
+
+1. Definitions
+--------------
+
+1.1. "Contributor"
+    means each individual or legal entity that creates, contributes to
+    the creation of, or owns Covered Software.
+
+1.2. "Contributor Version"
+    means the combination of the Contributions of others (if any) used
+    by a Contributor and that particular Contributor's Contribution.
+
+1.3. "Contribution"
+    means Covered Software of a particular Contributor.
+
+1.4. "Covered Software"
+    means Source Code Form to which the initial Contributor has attached
+    the notice in Exhibit A, the Executable Form of such Source Code
+    Form, and Modifications of such Source Code Form, in each case
+    including portions thereof.
+
+1.5. "Incompatible With Secondary Licenses"
+    means
+
+    (a) that the initial Contributor has attached the notice described
+        in Exhibit B to the Covered Software; or
+
+    (b) that the Covered Software was made available under the terms of
+        version 1.1 or earlier of the License, but not also under the
+        terms of a Secondary License.
+
+1.6. "Executable Form"
+    means any form of the work other than Source Code Form.
+
+1.7. "Larger Work"
+    means a work that combines Covered Software with other material, in
+    a separate file or files, that is not Covered Software.
+
+1.8. "License"
+    means this document.
+
+1.9. "Licensable"
+    means having the right to grant, to the maximum extent possible,
+    whether at the time of the initial grant or subsequently, any and
+    all of the rights conveyed by this License.
+
+1.10. "Modifications"
+    means any of the following:
+
+    (a) any file in Source Code Form that results from an addition to,
+        deletion from, or modification of the contents of Covered
+        Software; or
+
+    (b) any new file in Source Code Form that contains any Covered
+        Software.
+
+1.11. "Patent Claims" of a Contributor
+    means any patent claim(s), including without limitation, method,
+    process, and apparatus claims, in any patent Licensable by such
+    Contributor that would be infringed, but for the grant of the
+    License, by the making, using, selling, offering for sale, having
+    made, import, or transfer of either its Contributions or its
+    Contributor Version.
+
+1.12. "Secondary License"
+    means either the GNU General Public License, Version 2.0, the GNU
+    Lesser General Public License, Version 2.1, the GNU Affero General
+    Public License, Version 3.0, or any later versions of those
+    licenses.
+
+1.13. "Source Code Form"
+    means the form of the work preferred for making modifications.
+
+1.14. "You" (or "Your")
+    means an individual or a legal entity exercising rights under this
+    License. For legal entities, "You" includes any entity that
+    controls, is controlled by, or is under common control with You. For
+    purposes of this definition, "control" means (a) the power, direct
+    or indirect, to cause the direction or management of such entity,
+    whether by contract or otherwise, or (b) ownership of more than
+    fifty percent (50%) of the outstanding shares or beneficial
+    ownership of such entity.
+
+2. License Grants and Conditions
+--------------------------------
+
+2.1. Grants
+
+Each Contributor hereby grants You a world-wide, royalty-free,
+non-exclusive license:
+
+(a) under intellectual property rights (other than patent or trademark)
+    Licensable by such Contributor to use, reproduce, make available,
+    modify, display, perform, distribute, and otherwise exploit its
+    Contributions, either on an unmodified basis, with Modifications, or
+    as part of a Larger Work; and
+
+(b) under Patent Claims of such Contributor to make, use, sell, offer
+    for sale, have made, import, and otherwise transfer either its
+    Contributions or its Contributor Version.
+
+2.2. Effective Date
+
+The licenses granted in Section 2.1 with respect to any Contribution
+become effective for each Contribution on the date the Contributor first
+distributes such Contribution.
+
+2.3. Limitations on Grant Scope
+
+The licenses granted in this Section 2 are the only rights granted under
+this License. No additional rights or licenses will be implied from the
+distribution or licensing of Covered Software under this License.
+Notwithstanding Section 2.1(b) above, no patent license is granted by a
+Contributor:
+
+(a) for any code that a Contributor has removed from Covered Software;
+    or
+
+(b) for infringements caused by: (i) Your and any other third party's
+    modifications of Covered Software, or (ii) the combination of its
+    Contributions with other software (except as part of its Contributor
+    Version); or
+
+(c) under Patent Claims infringed by Covered Software in the absence of
+    its Contributions.
+
+This License does not grant any rights in the trademarks, service marks,
+or logos of any Contributor (except as may be necessary to comply with
+the notice requirements in Section 3.4).
+
+2.4. Subsequent Licenses
+
+No Contributor makes additional grants as a result of Your choice to
+distribute the Covered Software under a subsequent version of this
+License (see Section 10.2) or under the terms of a Secondary License (if
+permitted under the terms of Section 3.3).
+
+2.5. Representation
+
+Each Contributor represents that the Contributor believes its
+Contributions are its original creation(s) or it has sufficient rights
+to grant the rights to its Contributions conveyed by this License.
+
+2.6. Fair Use
+
+This License is not intended to limit any rights You have under
+applicable copyright doctrines of fair use, fair dealing, or other
+equivalents.
+
+2.7. Conditions
+
+Sections 3.1, 3.2, 3.3, and 3.4 are conditions of the licenses granted
+in Section 2.1.
+
+3. Responsibilities
+-------------------
+
+3.1. Distribution of Source Form
+
+All distribution of Covered Software in Source Code Form, including any
+Modifications that You create or to which You contribute, must be under
+the terms of this License. You must inform recipients that the Source
+Code Form of the Covered Software is governed by the terms of this
+License, and how they can obtain a copy of this License. You may not
+attempt to alter or restrict the recipients' rights in the Source Code
+Form.
+
+3.2. Distribution of Executable Form
+
+If You distribute Covered Software in Executable Form then:
+
+(a) such Covered Software must also be made available in Source Code
+    Form, as described in Section 3.1, and You must inform recipients of
+    the Executable Form how they can obtain a copy of such Source Code
+    Form by reasonable means in a timely manner, at a charge no more
+    than the cost of distribution to the recipient; and
+
+(b) You may distribute such Executable Form under the terms of this
+    License, or sublicense it under different terms, provided that the
+    license for the Executable Form does not attempt to limit or alter
+    the recipients' rights in the Source Code Form under this License.
+
+3.3. Distribution of a Larger Work
+
+You may create and distribute a Larger Work under terms of Your choice,
+provided that You also comply with the requirements of this License for
+the Covered Software. If the Larger Work is a combination of Covered
+Software with a work governed by one or more Secondary Licenses, and the
+Covered Software is not Incompatible With Secondary Licenses, this
+License permits You to additionally distribute such Covered Software
+under the terms of such Secondary License(s), so that the recipient of
+the Larger Work may, at their option, further distribute the Covered
+Software under the terms of either this License or such Secondary
+License(s).
+
+3.4. Notices
+
+You may not remove or alter the substance of any license notices
+(including copyright notices, patent notices, disclaimers of warranty,
+or limitations of liability) contained within the Source Code Form of
+the Covered Software, except that You may alter any license notices to
+the extent required to remedy known factual inaccuracies.
+
+3.5. Application of Additional Terms
+
+You may choose to offer, and to charge a fee for, warranty, support,
+indemnity or liability obligations to one or more recipients of Covered
+Software. However, You may do so only on Your own behalf, and not on
+behalf of any Contributor. You must make it absolutely clear that any
+such warranty, support, indemnity, or liability obligation is offered by
+You alone, and You hereby agree to indemnify every Contributor for any
+liability incurred by such Contributor as a result of warranty, support,
+indemnity or liability terms You offer. You may include additional
+disclaimers of warranty and limitations of liability specific to any
+jurisdiction.
+
+4. Inability to Comply Due to Statute or Regulation
+---------------------------------------------------
+
+If it is impossible for You to comply with any of the terms of this
+License with respect to some or all of the Covered Software due to
+statute, judicial order, or regulation then You must: (a) comply with
+the terms of this License to the maximum extent possible; and (b)
+describe the limitations and the code they affect. Such description must
+be placed in a text file included with all distributions of the Covered
+Software under this License. Except to the extent prohibited by statute
+or regulation, such description must be sufficiently detailed for a
+recipient of ordinary skill to be able to understand it.
+
+5. Termination
+--------------
+
+5.1. The rights granted under this License will terminate automatically
+if You fail to comply with any of its terms. However, if You become
+compliant, then the rights granted under this License from a particular
+Contributor are reinstated (a) provisionally, unless and until such
+Contributor explicitly and finally terminates Your grants, and (b) on an
+ongoing basis, if such Contributor fails to notify You of the
+non-compliance by some reasonable means prior to 60 days after You have
+come back into compliance. Moreover, Your grants from a particular
+Contributor are reinstated on an ongoing basis if such Contributor
+notifies You of the non-compliance by some reasonable means, this is the
+first time You have received notice of non-compliance with this License
+from such Contributor, and You become compliant prior to 30 days after
+Your receipt of the notice.
+
+5.2. If You initiate litigation against any entity by asserting a patent
+infringement claim (excluding declaratory judgment actions,
+counter-claims, and cross-claims) alleging that a Contributor Version
+directly or indirectly infringes any patent, then the rights granted to
+You by any and all Contributors for the Covered Software under Section
+2.1 of this License shall terminate.
+
+5.3. In the event of termination under Sections 5.1 or 5.2 above, all
+end user license agreements (excluding distributors and resellers) which
+have been validly granted by You or Your distributors under this License
+prior to termination shall survive termination.
+
+************************************************************************
+*                                                                      *
+*  6. Disclaimer of Warranty                                           *
+*  -------------------------                                           *
+*                                                                      *
+*  Covered Software is provided under this License on an "as is"       *
+*  basis, without warranty of any kind, either expressed, implied, or  *
+*  statutory, including, without limitation, warranties that the       *
+*  Covered Software is free of defects, merchantable, fit for a        *
+*  particular purpose or non-infringing. The entire risk as to the     *
+*  quality and performance of the Covered Software is with You.        *
+*  Should any Covered Software prove defective in any respect, You     *
+*  (not any Contributor) assume the cost of any necessary servicing,   *
+*  repair, or correction. This disclaimer of warranty constitutes an   *
+*  essential part of this License. No use of any Covered Software is   *
+*  authorized under this License except under this disclaimer.         *
+*                                                                      *
+************************************************************************
+
+************************************************************************
+*                                                                      *
+*  7. Limitation of Liability                                          *
+*  --------------------------                                          *
+*                                                                      *
+*  Under no circumstances and under no legal theory, whether tort      *
+*  (including negligence), contract, or otherwise, shall any           *
+*  Contributor, or anyone who distributes Covered Software as          *
+*  permitted above, be liable to You for any direct, indirect,         *
+*  special, incidental, or consequential damages of any character      *
+*  including, without limitation, damages for lost profits, loss of    *
+*  goodwill, work stoppage, computer failure or malfunction, or any    *
+*  and all other commercial damages or losses, even if such party      *
+*  shall have been informed of the possibility of such damages. This   *
+*  limitation of liability shall not apply to liability for death or   *
+*  personal injury resulting from such party's negligence to the       *
+*  extent applicable law prohibits such limitation. Some               *
+*  jurisdictions do not allow the exclusion or limitation of           *
+*  incidental or consequential damages, so this exclusion and          *
+*  limitation may not apply to You.                                    *
+*                                                                      *
+************************************************************************
+
+8. Litigation
+-------------
+
+Any litigation relating to this License may be brought only in the
+courts of a jurisdiction where the defendant maintains its principal
+place of business and such litigation shall be governed by laws of that
+jurisdiction, without reference to its conflict-of-law provisions.
+Nothing in this Section shall prevent a party's ability to bring
+cross-claims or counter-claims.
+
+9. Miscellaneous
+----------------
+
+This License represents the complete agreement concerning the subject
+matter hereof. If any provision of this License is held to be
+unenforceable, such provision shall be reformed only to the extent
+necessary to make it enforceable. Any law or regulation which provides
+that the language of a contract shall be construed against the drafter
+shall not be used to construe this License against a Contributor.
+
+10. Versions of the License
+---------------------------
+
+10.1. New Versions
+
+Mozilla Foundation is the license steward. Except as provided in Section
+10.3, no one other than the license steward has the right to modify or
+publish new versions of this License. Each version will be given a
+distinguishing version number.
+
+10.2. Effect of New Versions
+
+You may distribute the Covered Software under the terms of the version
+of the License under which You originally received the Covered Software,
+or under the terms of any subsequent version published by the license
+steward.
+
+10.3. Modified Versions
+
+If you create software not governed by this License, and you want to
+create a new license for such software, you may create and use a
+modified version of this License if you rename the license and remove
+any references to the name of the license steward (except to note that
+such modified license differs from this License).
+
+10.4. Distributing Source Code Form that is Incompatible With Secondary
+Licenses
+
+If You choose to distribute Source Code Form that is Incompatible With
+Secondary Licenses under the terms of this version of the License, the
+notice described in Exhibit B of this License must be attached.
+
+Exhibit A - Source Code Form License Notice
+-------------------------------------------
+
+  This Source Code Form is subject to the terms of the Mozilla Public
+  License, v. 2.0. If a copy of the MPL was not distributed with this
+  file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+If it is not possible or desirable to put the notice in a particular
+file, then You may include the notice in a location (such as a LICENSE
+file in a relevant directory) where a recipient would be likely to look
+for such a notice.
+
+You may add additional accurate notices of copyright ownership.
+
+Exhibit B - "Incompatible With Secondary Licenses" Notice
+---------------------------------------------------------
+
+  This Source Code Form is "Incompatible With Secondary Licenses", as
+  defined by the Mozilla Public License, v. 2.0.
diff --git a/recipes/recipes_emscripten/numpy-openblas/config/_numpyconfig.h b/recipes/recipes_emscripten/numpy-openblas/config/_numpyconfig.h
new file mode 100644
index 00000000000..7bb42603f2a
--- /dev/null
+++ b/recipes/recipes_emscripten/numpy-openblas/config/_numpyconfig.h
@@ -0,0 +1,30 @@
+#define NPY_HAVE_ENDIAN_H 1
+#define NPY_SIZEOF_SHORT 2
+#define NPY_SIZEOF_INT 4
+#define NPY_SIZEOF_LONG 4
+#define NPY_SIZEOF_FLOAT 4
+#define NPY_SIZEOF_COMPLEX_FLOAT 8
+#define NPY_SIZEOF_DOUBLE 8
+#define NPY_SIZEOF_COMPLEX_DOUBLE 16
+#define NPY_SIZEOF_LONGDOUBLE 8
+#define NPY_SIZEOF_COMPLEX_LONGDOUBLE 16
+#define NPY_SIZEOF_PY_INTPTR_T 4
+#define NPY_SIZEOF_OFF_T 4
+#define NPY_SIZEOF_PY_LONG_LONG 8
+#define NPY_SIZEOF_LONGLONG 8
+#define NPY_NO_SMP 0
+#define NPY_HAVE_DECL_ISNAN
+#define NPY_HAVE_DECL_ISINF
+#define NPY_HAVE_DECL_ISFINITE
+#define NPY_HAVE_DECL_SIGNBIT
+#define NPY_USE_C99_COMPLEX 1
+#define NPY_HAVE_COMPLEX_DOUBLE 1
+#define NPY_HAVE_COMPLEX_FLOAT 1
+#define NPY_HAVE_COMPLEX_LONG_DOUBLE 1
+#define NPY_RELAXED_STRIDES_CHECKING 1
+#define NPY_USE_C99_FORMATS 1
+#define NPY_VISIBILITY_HIDDEN __attribute__((visibility("hidden")))
+
+#ifndef __STDC_FORMAT_MACROS
+#define __STDC_FORMAT_MACROS 1
+#endif
diff --git a/recipes/recipes_emscripten/numpy-openblas/config/config.h.in b/recipes/recipes_emscripten/numpy-openblas/config/config.h.in
new file mode 100644
index 00000000000..313299eb75e
--- /dev/null
+++ b/recipes/recipes_emscripten/numpy-openblas/config/config.h.in
@@ -0,0 +1,119 @@
+#mesondefine SIZEOF_PY_INTPTR_T
+#mesondefine SIZEOF_OFF_T
+#mesondefine SIZEOF_PY_LONG_LONG
+
+#undef HAVE_BACKTRACE
+#mesondefine HAVE_MADVISE
+#mesondefine HAVE_FTELLO
+#mesondefine HAVE_FSEEKO
+#mesondefine HAVE_FALLOCATE
+#mesondefine HAVE_STRTOLD_L
+#mesondefine HAVE_THREAD_LOCAL
+#mesondefine HAVE__THREAD_LOCAL
+#mesondefine HAVE__THREAD
+#mesondefine HAVE___DECLSPEC_THREAD_
+
+/* Optional headers */
+#mesondefine HAVE_FEATURES_H
+#mesondefine HAVE_XLOCALE_H
+#mesondefine HAVE_DLFCN_H
+#mesondefine HAVE_EXECINFO_H
+#mesondefine HAVE_LIBUNWIND_H
+#mesondefine HAVE_SYS_MMAN_H
+#mesondefine HAVE_XMMINTRIN_H
+#mesondefine HAVE_EMMINTRIN_H
+#mesondefine HAVE_IMMINTRIN_H
+
+/* Optional intrinsics */
+#mesondefine HAVE___BUILTIN_ISNAN
+#mesondefine HAVE___BUILTIN_ISINF
+#mesondefine HAVE___BUILTIN_ISFINITE
+#mesondefine HAVE___BUILTIN_BSWAP32
+#mesondefine HAVE___BUILTIN_BSWAP64
+#mesondefine HAVE___BUILTIN_EXPECT
+#mesondefine HAVE___BUILTIN_MUL_OVERFLOW
+#mesondefine HAVE___BUILTIN_PREFETCH
+
+#mesondefine HAVE_ATTRIBUTE_OPTIMIZE_UNROLL_LOOPS
+#mesondefine HAVE_ATTRIBUTE_OPTIMIZE_OPT_3
+#mesondefine HAVE_ATTRIBUTE_OPTIMIZE_OPT_2
+#mesondefine HAVE_ATTRIBUTE_NONNULL
+
+/* C99 complex support and complex.h are not universal */
+#mesondefine HAVE_CABS
+#mesondefine HAVE_CACOS
+#mesondefine HAVE_CACOSH
+#mesondefine HAVE_CARG
+#mesondefine HAVE_CASIN
+#mesondefine HAVE_CASINH
+#mesondefine HAVE_CATAN
+#mesondefine HAVE_CATANH
+#mesondefine HAVE_CEXP
+#mesondefine HAVE_CLOG
+#mesondefine HAVE_CPOW
+#mesondefine HAVE_CSQRT
+#mesondefine HAVE_CABSF
+#mesondefine HAVE_CACOSF
+#mesondefine HAVE_CACOSHF
+#mesondefine HAVE_CARGF
+#mesondefine HAVE_CASINF
+#mesondefine HAVE_CASINHF
+#mesondefine HAVE_CATANF
+#mesondefine HAVE_CATANHF
+#mesondefine HAVE_CEXPF
+#mesondefine HAVE_CLOGF
+#mesondefine HAVE_CPOWF
+#mesondefine HAVE_CSQRTF
+#mesondefine HAVE_CABSL
+#mesondefine HAVE_CACOSL
+#mesondefine HAVE_CACOSHL
+#mesondefine HAVE_CARGL
+#mesondefine HAVE_CASINL
+#mesondefine HAVE_CASINHL
+#mesondefine HAVE_CATANL
+#mesondefine HAVE_CATANHL
+#mesondefine HAVE_CEXPL
+#mesondefine HAVE_CLOGL
+#mesondefine HAVE_CPOWL
+#mesondefine HAVE_CSQRTL
+/* FreeBSD */
+#mesondefine HAVE_CSINF
+#mesondefine HAVE_CSINHF
+#mesondefine HAVE_CCOSF
+#mesondefine HAVE_CCOSHF
+#mesondefine HAVE_CTANF
+#mesondefine HAVE_CTANHF
+#mesondefine HAVE_CSIN
+#mesondefine HAVE_CSINH
+#mesondefine HAVE_CCOS
+#mesondefine HAVE_CCOSH
+#mesondefine HAVE_CTAN
+#mesondefine HAVE_CTANH
+#mesondefine HAVE_CSINL
+#mesondefine HAVE_CSINHL
+#mesondefine HAVE_CCOSL
+#mesondefine HAVE_CCOSHL
+#mesondefine HAVE_CTANL
+#mesondefine HAVE_CTANHL
+
+#mesondefine NPY_CAN_LINK_SVML
+
+#mesondefine HAVE_LDOUBLE_INTEL_EXTENDED_16_BYTES_LE
+#mesondefine HAVE_LDOUBLE_INTEL_EXTENDED_12_BYTES_LE
+#mesondefine HAVE_LDOUBLE_MOTOROLA_EXTENDED_12_BYTES_BE
+#mesondefine HAVE_LDOUBLE_IEEE_DOUBLE_LE
+#mesondefine HAVE_LDOUBLE_IEEE_DOUBLE_BE
+#mesondefine HAVE_LDOUBLE_IEEE_QUAD_LE
+#mesondefine HAVE_LDOUBLE_IEEE_QUAD_BE
+#mesondefine HAVE_LDOUBLE_IBM_DOUBLE_DOUBLE_LE
+#mesondefine HAVE_LDOUBLE_IBM_DOUBLE_DOUBLE_BE
+
+#mesondefine HAVE_EXTERNAL_LAPACK
+
+#ifndef __cplusplus
+/* #undef inline */
+#endif
+
+#ifndef NUMPY_CORE_SRC_COMMON_NPY_CONFIG_H_
+#error config.h should never be included directly, include npy_config.h instead
+#endif
\ No newline at end of file
diff --git a/recipes/recipes_emscripten/numpy-openblas/emscripten.meson.cross b/recipes/recipes_emscripten/numpy-openblas/emscripten.meson.cross
new file mode 100644
index 00000000000..13d8b5fa287
--- /dev/null
+++ b/recipes/recipes_emscripten/numpy-openblas/emscripten.meson.cross
@@ -0,0 +1,62 @@
+[binaries]
+exe_wrapper = 'node'
+pkg-config = 'pkg-config'
+
+[properties]
+needs_exe_wrapper = true
+skip_sanity_check = true
+longdouble_format = 'IEEE_QUAD_LE' # for numpy
+has_function_sin = true
+has_function_cos = true
+has_function_tan = true
+has_function_log = true
+has_function_exp = true
+has_function_sqrt = true
+has_function_pow = true
+has_function_fmod = true
+has_function_atan2 = true
+has_function_hypot = true
+has_function_copysign = true
+has_function_modf = true
+has_function_frexp = true
+has_function_sinh = true
+has_function_cosh = true
+has_function_tanh = true
+has_function_fabs = true
+has_function_floor = true
+has_function_ceil = true
+has_function_log10 = true
+has_function_asin = true
+has_function_acos = true
+has_function_atan = true
+has_function_ldexp = true
+has_function_expm1 = true
+has_function_log1p = true
+has_function_acosh = true
+has_function_asinh = true
+has_function_atanh = true
+has_function_rint = true
+has_function_trunc = true
+has_function_exp2 = true
+has_function_nextafter = true
+has_function_cbrt = true
+has_function_log2 = true
+has_function_csin = true
+has_function_csinh = true
+has_function_ccos = true
+has_function_ccosh = true
+has_function_ctan = true
+has_function_ctanh = true
+has_function_creal = true
+has_function_cimag = true
+has_function_conj = true
+has_function_strtoll = true
+has_function_strtod = true
+has_function_strtoul = true
+has_function_strtoull = true
+has_function_strtof = true
+[host_machine]
+system = 'emscripten'
+cpu_family = 'wasm32'
+cpu = 'wasm'
+endian = 'little'
diff --git a/recipes/recipes_emscripten/numpy/fix_flang_fortran_abi.py b/recipes/recipes_emscripten/numpy-openblas/fix_flang_fortran_abi.py
similarity index 100%
rename from recipes/recipes_emscripten/numpy/fix_flang_fortran_abi.py
rename to recipes/recipes_emscripten/numpy-openblas/fix_flang_fortran_abi.py
diff --git a/recipes/recipes_emscripten/numpy/patches/0001-Match-flang-OpenBLAS-Fortran-ABI-on-Emscripten-wasm32.patch b/recipes/recipes_emscripten/numpy-openblas/patches/0001-Match-flang-OpenBLAS-Fortran-ABI-on-Emscripten-wasm32.patch
similarity index 100%
rename from recipes/recipes_emscripten/numpy/patches/0001-Match-flang-OpenBLAS-Fortran-ABI-on-Emscripten-wasm32.patch
rename to recipes/recipes_emscripten/numpy-openblas/patches/0001-Match-flang-OpenBLAS-Fortran-ABI-on-Emscripten-wasm32.patch
diff --git a/recipes/recipes_emscripten/numpy-openblas/recipe.yaml b/recipes/recipes_emscripten/numpy-openblas/recipe.yaml
new file mode 100644
index 00000000000..5b7ae968c46
--- /dev/null
+++ b/recipes/recipes_emscripten/numpy-openblas/recipe.yaml
@@ -0,0 +1,67 @@
+context:
+  version: 2.5.1
+  cross_target_plattform: emscripten-wasm32
+  target_plattform: emscripten-wasm32
+  default_abi_level: 2.2
+
+package:
+  name: numpy
+  version: ${{ version }}
+source:
+  url: https://github.com/numpy/numpy/releases/download/v${{ version }}/numpy-${{ version }}.tar.gz
+  sha256: a48a113e6afea91f5608793bafa7ef2ad481fefbda87ec5069f483de61cb9fa3
+  patches:
+  - patches/0001-Match-flang-OpenBLAS-Fortran-ABI-on-Emscripten-wasm32.patch
+build:
+  number: 1
+
+  files:
+    exclude:
+    - '**/*.pyi'
+    - '**/tests/**'
+    - '**/*.ini'
+    - '**/__pycache__/**'
+    - '**/*.pyc'
+    - '**/test_*.py'
+  python:
+    skip_pyc_compilation:
+    - '**/*.py'
+requirements:
+  build:
+  - ${{ compiler("c") }}
+  - cross-python_${{target_platform}}
+  - cython >=3.0.6
+  - meson-python >=0.18.0
+  - ninja >=1.8.2
+  - pip >=24.0
+  - pkg-config
+  - python
+  host:
+  - openblas
+  - python
+  run:
+  - openblas
+  - python
+  run_exports:
+  - numpy >=${{ default_abi_level }},<3
+tests:
+- script: pytester
+  requirements:
+    build:
+    - pytester
+    run:
+    - pytester-run
+  files:
+    recipe:
+    - test_numpy.py
+
+about:
+  homepage: http://numpy.org/
+  license: BSD-3-Clause
+  license_file: LICENSE.txt
+  summary: The fundamental package for scientific computing with Python.
+
+extra:
+  recipe-maintainers:
+  - DerThorsten
+  channel: emscripten-forge-4x-experimental
\ No newline at end of file
diff --git a/recipes/recipes_emscripten/numpy-openblas/test_numpy.py b/recipes/recipes_emscripten/numpy-openblas/test_numpy.py
new file mode 100644
index 00000000000..469f6aef97e
--- /dev/null
+++ b/recipes/recipes_emscripten/numpy-openblas/test_numpy.py
@@ -0,0 +1,60 @@
+import numpy as np
+from numpy.testing import assert_allclose
+
+
+def test_numpy():
+    ones = np.ones(shape=[2, 3])
+    assert ones.shape == (2, 3)
+
+
+def test_openblas_build_config():
+    cfg = np.show_config(mode="dicts")
+    blas = cfg["Build Dependencies"]["blas"]
+    lapack = cfg["Build Dependencies"]["lapack"]
+    assert blas["found"] is True
+    assert lapack["found"] is True
+    # scipy-openblas.pc alias is used to bypass Meson's OpenBLAS factory.
+    assert "openblas" in blas["name"]
+    assert "openblas configuration" in blas
+    assert blas["openblas configuration"] != "unknown"
+
+
+# Large enough that OpenBLAS blocked kernels are exercised (not tiny fallbacks).
+N = 300
+
+
+def test_blas_matmul():
+    rng = np.random.default_rng(0)
+    a = rng.standard_normal((N, N))
+    b = rng.standard_normal((N, N))
+    c = a @ b
+    assert c.shape == (N, N)
+    assert_allclose(c, np.dot(a, b))
+    assert_allclose(c.T, b.T @ a.T)
+
+
+def test_lapack_cholesky():
+    rng = np.random.default_rng(1)
+    x = rng.standard_normal((N, N))
+    a = x @ x.T + N * np.eye(N)
+    l = np.linalg.cholesky(a)
+    assert_allclose(l @ l.T, a)
+
+
+def test_lapack_solve():
+    rng = np.random.default_rng(2)
+    a = rng.standard_normal((N, N))
+    b = rng.standard_normal(N)
+    x = np.linalg.solve(a, b)
+    assert_allclose(a @ x, b)
+
+
+def test_lapack_eigh():
+    rng = np.random.default_rng(3)
+    x = rng.standard_normal((N, N))
+    a = x @ x.T
+    evals, evecs = np.linalg.eigh(a)
+    assert evals.shape == (N,)
+    assert evecs.shape == (N, N)
+    assert_allclose(evecs.T @ evecs, np.eye(N), atol=1e-8)
+    assert_allclose(evecs @ np.diag(evals) @ evecs.T, a)
diff --git a/recipes/recipes_emscripten/numpy/build.sh b/recipes/recipes_emscripten/numpy/build.sh
index 6acdcb31041..5b26306b9c9 100644
--- a/recipes/recipes_emscripten/numpy/build.sh
+++ b/recipes/recipes_emscripten/numpy/build.sh
@@ -1,59 +1,26 @@
 #!/bin/bash
 
-set -ex
-
 echo "PYTHON"
 
 rm -r -f branding
 
-# Prefer the relocatable openblas.pc shipped by the openblas package.
-export PKG_CONFIG_PATH="${PREFIX}/lib/pkgconfig${PKG_CONFIG_PATH:+:${PKG_CONFIG_PATH}}"
-
-# NumPy tries dependency('scipy-openblas', method: 'pkg-config') before
-# dependency('openblas'). That name is not registered in Meson's BLAS
-# factory, so it avoids wasm-ld-breaking void dgemm_() symbol probes.
-# OpenBLAS only ships openblas.pc; provide a build-local alias derived
-# from it (rewrite prefix to $PREFIX — pcfiledir would be wrong here).
-PKGCONFIG_DIR="${SRC_DIR}/.emscripten-pkgconfig"
-mkdir -p "${PKGCONFIG_DIR}"
-sed -e "s|^prefix=.*|prefix=${PREFIX}|" \
-    -e 's/^Name: .*/Name: scipy-openblas/' \
-    "${PREFIX}/lib/pkgconfig/openblas.pc" \
-    > "${PKGCONFIG_DIR}/scipy-openblas.pc"
-export PKG_CONFIG_PATH="${PKGCONFIG_DIR}:${PKG_CONFIG_PATH}"
-
-# Fail early if OpenBLAS is not usable from pkg-config.
-pkg-config --exists --print-errors openblas
-pkg-config --exists --print-errors scipy-openblas
-pkg-config --cflags --libs openblas
-test -f "${PREFIX}/include/cblas.h"
-test -f "${PREFIX}/lib/libopenblas.so"
-
-# Cross builds do not always inherit PKG_CONFIG_PATH; tell Meson where to look.
-cp "${RECIPE_DIR}/emscripten.meson.cross" "${SRC_DIR}/emscripten.meson.cross"
-cat >> "${SRC_DIR}/emscripten.meson.cross" <<EOF
-
-[built-in options]
-pkg_config_path = ['${PKGCONFIG_DIR}', '${PREFIX}/lib/pkgconfig']
-EOF
-export MESON_CROSS_FILE="${SRC_DIR}/emscripten.meson.cross"
-
 export CFLAGS="$CFLAGS -Wno-return-type -Wno-implicit-function-declaration -msimd128 -fwasm-exceptions -s SUPPORT_LONGJMP"
+export MESON_CROSS_FILE=$RECIPE_DIR/emscripten.meson.cross 
 export LDFLAGS="$LDFLAGS -sWASM_BIGINT 	-s WASM_BIGINT -fwasm-exceptions -s SUPPORT_LONGJMP"
 
 cp $RECIPE_DIR/config/config.h.in  numpy/_core/config.h.in
+# 
 
 # otherwise "cython" is not properly executable
 echo "add shebang to cython file"
 sed -i '1i#!/usr/bin/env python' $BUILD_PREFIX/bin/cython
 
+
+
 # replace -fexceptions with -fwasm-exceptions in numpy/_core
 sed -i 's/-fexceptions/-fwasm-exceptions/g' numpy/_core/meson.build
 
-# -Dblas=openblas makes NumPy try scipy-openblas first (see numpy/meson.build).
-# allow-noblas defaults to true; force OpenBLAS to be required.
-${PYTHON} -m pip install . -vvv --no-deps --no-build-isolation \
-    -Csetup-args="-Dblas=openblas" \
-    -Csetup-args="-Dlapack=openblas" \
-    -Csetup-args="-Dallow-noblas=false" \
+
+MESON_ARGS="-Dhave_backtrace=false" ${PYTHON} -m pip install . -vvv --no-deps --no-build-isolation \
+    -Csetup-args="-Dallow-noblas=true" \
     -Csetup-args="--cross-file=$MESON_CROSS_FILE"
diff --git a/recipes/recipes_emscripten/numpy/emscripten.meson.cross b/recipes/recipes_emscripten/numpy/emscripten.meson.cross
index 13d8b5fa287..5ef99c56d35 100644
--- a/recipes/recipes_emscripten/numpy/emscripten.meson.cross
+++ b/recipes/recipes_emscripten/numpy/emscripten.meson.cross
@@ -1,6 +1,6 @@
 [binaries]
 exe_wrapper = 'node'
-pkg-config = 'pkg-config'
+pkgconfig = 'pkg-config'
 
 [properties]
 needs_exe_wrapper = true
diff --git a/recipes/recipes_emscripten/numpy/recipe.yaml b/recipes/recipes_emscripten/numpy/recipe.yaml
index 5b7ae968c46..62346d5e6c3 100644
--- a/recipes/recipes_emscripten/numpy/recipe.yaml
+++ b/recipes/recipes_emscripten/numpy/recipe.yaml
@@ -10,10 +10,8 @@ package:
 source:
   url: https://github.com/numpy/numpy/releases/download/v${{ version }}/numpy-${{ version }}.tar.gz
   sha256: a48a113e6afea91f5608793bafa7ef2ad481fefbda87ec5069f483de61cb9fa3
-  patches:
-  - patches/0001-Match-flang-OpenBLAS-Fortran-ABI-on-Emscripten-wasm32.patch
 build:
-  number: 1
+  number: 0
 
   files:
     exclude:
@@ -37,10 +35,6 @@ requirements:
   - pkg-config
   - python
   host:
-  - openblas
-  - python
-  run:
-  - openblas
   - python
   run_exports:
   - numpy >=${{ default_abi_level }},<3
@@ -64,4 +58,3 @@ about:
 extra:
   recipe-maintainers:
   - DerThorsten
-  channel: emscripten-forge-4x-experimental
\ No newline at end of file
diff --git a/recipes/recipes_emscripten/numpy/test_numpy.py b/recipes/recipes_emscripten/numpy/test_numpy.py
index 469f6aef97e..839ca268a61 100644
--- a/recipes/recipes_emscripten/numpy/test_numpy.py
+++ b/recipes/recipes_emscripten/numpy/test_numpy.py
@@ -1,60 +1,5 @@
-import numpy as np
-from numpy.testing import assert_allclose
-
-
 def test_numpy():
-    ones = np.ones(shape=[2, 3])
-    assert ones.shape == (2, 3)
-
-
-def test_openblas_build_config():
-    cfg = np.show_config(mode="dicts")
-    blas = cfg["Build Dependencies"]["blas"]
-    lapack = cfg["Build Dependencies"]["lapack"]
-    assert blas["found"] is True
-    assert lapack["found"] is True
-    # scipy-openblas.pc alias is used to bypass Meson's OpenBLAS factory.
-    assert "openblas" in blas["name"]
-    assert "openblas configuration" in blas
-    assert blas["openblas configuration"] != "unknown"
-
-
-# Large enough that OpenBLAS blocked kernels are exercised (not tiny fallbacks).
-N = 300
-
-
-def test_blas_matmul():
-    rng = np.random.default_rng(0)
-    a = rng.standard_normal((N, N))
-    b = rng.standard_normal((N, N))
-    c = a @ b
-    assert c.shape == (N, N)
-    assert_allclose(c, np.dot(a, b))
-    assert_allclose(c.T, b.T @ a.T)
-
-
-def test_lapack_cholesky():
-    rng = np.random.default_rng(1)
-    x = rng.standard_normal((N, N))
-    a = x @ x.T + N * np.eye(N)
-    l = np.linalg.cholesky(a)
-    assert_allclose(l @ l.T, a)
-
-
-def test_lapack_solve():
-    rng = np.random.default_rng(2)
-    a = rng.standard_normal((N, N))
-    b = rng.standard_normal(N)
-    x = np.linalg.solve(a, b)
-    assert_allclose(a @ x, b)
-
+    import numpy
 
-def test_lapack_eigh():
-    rng = np.random.default_rng(3)
-    x = rng.standard_normal((N, N))
-    a = x @ x.T
-    evals, evecs = np.linalg.eigh(a)
-    assert evals.shape == (N,)
-    assert evecs.shape == (N, N)
-    assert_allclose(evecs.T @ evecs, np.eye(N), atol=1e-8)
-    assert_allclose(evecs @ np.diag(evals) @ evecs.T, a)
+    ones = numpy.ones(shape=[2,3])
+    assert ones.shape == (2,3)
\ No newline at end of file

From 908ce299d17e759664cfae3af9002066861740b8 Mon Sep 17 00:00:00 2001
From: Julien Jerphanion <git@jjerphan.xyz>
Date: Mon, 10 Aug 2026 14:34:23 +0200
Subject: [PATCH 8/8] Add jjerphan to recipe maintainer

Signed-off-by: Julien Jerphanion <git@jjerphan.xyz>
---
 recipes/recipes_emscripten/numpy-openblas/recipe.yaml | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/recipes/recipes_emscripten/numpy-openblas/recipe.yaml b/recipes/recipes_emscripten/numpy-openblas/recipe.yaml
index 5b7ae968c46..7bfa7701ebf 100644
--- a/recipes/recipes_emscripten/numpy-openblas/recipe.yaml
+++ b/recipes/recipes_emscripten/numpy-openblas/recipe.yaml
@@ -64,4 +64,5 @@ about:
 extra:
   recipe-maintainers:
   - DerThorsten
-  channel: emscripten-forge-4x-experimental
\ No newline at end of file
+  - jjerphan
+  channel: emscripten-forge-4x-experimental