From 8a1b2d9861edeb2696ce2a1872ea46592c816ed7 Mon Sep 17 00:00:00 2001
From: Eelco Dolstra <edolstra@gmail.com>
Date: Sun, 5 Apr 2026 11:31:17 +0200
Subject: [PATCH] nix develop: Respect legacyPackages

---
 src/libcmd/builtin-flake-schemas.nix |  1 +
 tests/functional/flakes/develop.sh   | 17 +++++++++++++++++
 2 files changed, 18 insertions(+)

diff --git a/src/libcmd/builtin-flake-schemas.nix b/src/libcmd/builtin-flake-schemas.nix
index 0ee6d8f5ae39..39f09d92fa29 100644
--- a/src/libcmd/builtin-flake-schemas.nix
+++ b/src/libcmd/builtin-flake-schemas.nix
@@ -137,6 +137,7 @@
         roles.nix-build = { };
         roles.nix-run = { };
         roles.nix-search = { };
+        roles.nix-develop = { };
         appendSystem = true;
         inventory =
           output:
diff --git a/tests/functional/flakes/develop.sh b/tests/functional/flakes/develop.sh
index 0248adf49eaf..f37682be947f 100755
--- a/tests/functional/flakes/develop.sh
+++ b/tests/functional/flakes/develop.sh
@@ -192,3 +192,20 @@ sed -i "$TEST_HOME/flake.nix" -e 's/devShells/devShells2/' # remove devShells
 [[ $(nix develop . -L --command sh -c "echo \$x") == "bar" ]]
 sed -i "$TEST_HOME/flake.nix" -e 's/devShell/devShell2/' # remove devShell
 [[ $(nix develop . -L --command sh -c "echo \$x") == "xyzzy" ]]
+
+# Check that legacyPackages is used, but only when specifying an explicit package.
+cat <<EOF >"$TEST_HOME/flake.nix"
+{
+  inputs.nixpkgs.url = "$TEST_HOME/nixpkgs";
+  outputs = {self, nixpkgs}: {
+    legacyPackages.$system.default = (import ./config.nix).mkDerivation {
+      name = "hello";
+      buildCommand = "set -x; mkdir \$out";
+      x = "foo";
+    };
+  };
+}
+EOF
+
+(! nix develop . -L --command sh -c "echo \$x")
+[[ $(nix develop .#default -L --command sh -c "echo \$x") == "foo" ]]