From da13f57e70a791992f4715d982890728b04242e6 Mon Sep 17 00:00:00 2001
From: Katharine Hyatt <khyatt@flatironinstitute.org>
Date: Thu, 8 Oct 2026 08:31:19 -0400
Subject: [PATCH 1/2] Remove unneeded fwd tr rule

---
 ext/TensorKitEnzymeExt/linalg.jl | 24 ------------------------
 1 file changed, 24 deletions(-)

diff --git a/ext/TensorKitEnzymeExt/linalg.jl b/ext/TensorKitEnzymeExt/linalg.jl
index 232e58303..8401575e7 100644
--- a/ext/TensorKitEnzymeExt/linalg.jl
+++ b/ext/TensorKitEnzymeExt/linalg.jl
@@ -125,30 +125,6 @@ function EnzymeRules.reverse(
     )
     return (nothing,)
 end
-function EnzymeRules.forward(
-        config::EnzymeRules.FwdConfigWidth{1},
-        ::Type{RT},
-        func::Const{typeof(tr)},
-        A::Annotation{<:AbstractTensorMap},
-    ) where {RT}
-    y = EnzymeRules.needs_primal(config) ? tr(A.val) : nothing
-    Δy = if EnzymeRules.needs_shadow(config) && !isa(A, Const)
-        tr(A.dval)
-    elseif EnzymeRules.needs_shadow(config)
-        zero(eltype(A.dval))
-    else
-        nothing
-    end
-    if EnzymeRules.needs_primal(config) && EnzymeRules.needs_shadow(config)
-        return Duplicated(y, Δy)
-    elseif EnzymeRules.needs_primal(config)
-        return y
-    elseif EnzymeRules.needs_shadow(config)
-        return Δy
-    else
-        return nothing
-    end
-end
 function EnzymeRules.augmented_primal(
         config::EnzymeRules.RevConfigWidth{1},
         func::Const{typeof(norm)},

From 0546832ac39eb0b3613ad6f44b2a37e1385ecce3 Mon Sep 17 00:00:00 2001
From: Katharine Hyatt <khyatt@flatironinstitute.org>
Date: Thu, 8 Oct 2026 17:05:57 -0400
Subject: [PATCH 2/2] Drop twist rules

---
 ext/TensorKitEnzymeExt/indexmanipulations.jl | 51 --------------------
 1 file changed, 51 deletions(-)

diff --git a/ext/TensorKitEnzymeExt/indexmanipulations.jl b/ext/TensorKitEnzymeExt/indexmanipulations.jl
index 20439adaa..3a54a3230 100644
--- a/ext/TensorKitEnzymeExt/indexmanipulations.jl
+++ b/ext/TensorKitEnzymeExt/indexmanipulations.jl
@@ -183,57 +183,6 @@ function EnzymeRules.forward(
     end
 end
 
-# Differentiating through the fusion tree loop corrupts the
-# heap on Julia 1.10 and causes segfaults in the GC. Remove this
-# custom rule when we drop support for 1.10
-function EnzymeRules.augmented_primal(
-        config::EnzymeRules.RevConfigWidth{1},
-        func::Const{typeof(twist!)},
-        ::Type{RT},
-        t::Annotation{<:AbstractTensorMap},
-        inds::Const;
-        inv::Bool = false
-    ) where {RT}
-    twist!(t.val, inds.val; inv)
-    primal = EnzymeRules.needs_primal(config) ? t.val : nothing
-    shadow = EnzymeRules.needs_shadow(config) ? t.dval : nothing
-    return EnzymeRules.AugmentedReturn(primal, shadow, nothing)
-end
-
-function EnzymeRules.reverse(
-        config::EnzymeRules.RevConfigWidth{1},
-        func::Const{typeof(twist!)},
-        ::Type{RT},
-        cache,
-        t::Annotation{<:AbstractTensorMap},
-        inds::Const;
-        inv::Bool = false
-    ) where {RT}
-    !isa(t, Const) && twist!(t.dval, inds.val; inv = !inv)
-    return (nothing, nothing)
-end
-
-function EnzymeRules.forward(
-        config::EnzymeRules.FwdConfigWidth{1},
-        func::Const{typeof(twist!)},
-        ::Type{RT},
-        t::Annotation{<:AbstractTensorMap},
-        inds::Annotation;
-        inv::Bool = false
-    ) where {RT}
-    twist!(t.val, inds.val; inv)
-    !isa(t, Const) && twist!(t.dval, inds.val; inv)
-    if EnzymeRules.needs_primal(config) && EnzymeRules.needs_shadow(config)
-        return Duplicated(t.val, t.dval)
-    elseif EnzymeRules.needs_primal(config)
-        return t.val
-    elseif EnzymeRules.needs_shadow(config)
-        return t.dval
-    else
-        return nothing
-    end
-end
-
 function EnzymeRules.augmented_primal(
         config::EnzymeRules.RevConfigWidth{1},
         func::Const{typeof(flip)},