From 152208e4815590b5bf5e314f2008c7db35faa037 Mon Sep 17 00:00:00 2001
From: Romeo Valentin <romeov@stanford.edu>
Date: Fri, 1 Aug 2025 15:16:52 -0700
Subject: [PATCH 01/19] Start implementing trimming test

We introduce `SafeTestsets` as part of this, inspired by the way the
downstream tests are set up in the `SciMLBase` repo.
---
 Project.toml                        |  4 +--
 test/runtests.jl                    | 41 +++++++++++++++++++++++------
 test/trim/Project.toml              | 27 +++++++++++++++++++
 test/trim/clean_optimization.jl     | 32 ++++++++++++++++++++++
 test/trim/trimmable_optimization.jl | 35 ++++++++++++++++++++++++
 5 files changed, 129 insertions(+), 10 deletions(-)
 create mode 100644 test/trim/Project.toml
 create mode 100644 test/trim/clean_optimization.jl
 create mode 100644 test/trim/trimmable_optimization.jl

diff --git a/Project.toml b/Project.toml
index 1be25a8b7..a8dbaa9f6 100644
--- a/Project.toml
+++ b/Project.toml
@@ -143,6 +143,7 @@ PolyesterForwardDiff = "98d1487c-24ca-40b6-b7ab-df2af84e126b"
 Random = "9a3f8284-a2c9-5f02-9a11-845980a1fd5c"
 ReTestItems = "817f1d60-ba6b-4fd5-9520-3cf149f6a823"
 SIAMFANLEquations = "084e46ad-d928-497d-ad5e-07fa361a48c4"
+SafeTestsets = "1bc83da4-3b8d-516f-aca4-4fe02f6d838f"
 SparseConnectivityTracer = "9f842d2f-2579-4b1d-911e-f412cf18a3f5"
 SpeedMapping = "f1835b91-879b-4a3f-a438-e4baacf14412"
 StableRNGs = "860ef19b-820b-49d6-a774-d7a799459cd3"
@@ -170,5 +171,4 @@ path = "lib/NonlinearSolveSpectralMethods"
 path = "lib/SimpleNonlinearSolve"
 
 [targets]
-test = ["Aqua", "BandedMatrices", "BenchmarkTools", "CUDA", "Enzyme", "ExplicitImports", "FastLevenbergMarquardt", "FixedPointAcceleration", "Hwloc", "InteractiveUtils", "LeastSquaresOptim", "LineSearches", "MINPACK", "NLSolvers", "NLsolve", "NaNMath", "NonlinearProblemLibrary", "OrdinaryDiffEqTsit5", "PETSc", "Pkg", "PolyesterForwardDiff", "Random", "ReTestItems", "SIAMFANLEquations", "SparseConnectivityTracer", "SpeedMapping", "StableRNGs", "StaticArrays", "Sundials", "Test", "Zygote"]
-
+test = ["Aqua", "BandedMatrices", "BenchmarkTools", "CUDA", "Enzyme", "ExplicitImports", "FastLevenbergMarquardt", "FixedPointAcceleration", "Hwloc", "InteractiveUtils", "LeastSquaresOptim", "LineSearches", "MINPACK", "NLSolvers", "NLsolve", "NaNMath", "NonlinearProblemLibrary", "OrdinaryDiffEqTsit5", "PETSc", "Pkg", "PolyesterForwardDiff", "Random", "ReTestItems", "SafeTestsets", "SIAMFANLEquations", "SparseConnectivityTracer", "SpeedMapping", "StableRNGs", "StaticArrays", "Sundials", "Test", "Zygote"]
diff --git a/test/runtests.jl b/test/runtests.jl
index bfdd07b35..e1a928ae2 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -1,9 +1,18 @@
-using ReTestItems, NonlinearSolve, Hwloc, InteractiveUtils, Pkg
+using NonlinearSolve, Hwloc, InteractiveUtils, Pkg
+using SafeTestsets
+using ReTestItems
 
 @info sprint(InteractiveUtils.versioninfo)
 
 const GROUP = lowercase(get(ENV, "GROUP", "All"))
 
+function activate_trim_env!()
+    Pkg.activate(abspath(joinpath(dirname(@__FILE__), "trim")))
+    Pkg.develop(PackageSpec(path = dirname(@__DIR__)))
+    Pkg.instantiate()
+    return nothing
+end
+
 const EXTRA_PKGS = Pkg.PackageSpec[]
 if GROUP == "all" || GROUP == "downstream"
     push!(EXTRA_PKGS, Pkg.PackageSpec("ModelingToolkit"))
@@ -12,11 +21,13 @@ end
 length(EXTRA_PKGS) ≥ 1 && Pkg.add(EXTRA_PKGS)
 
 const RETESTITEMS_NWORKERS = parse(
-    Int, get(ENV, "RETESTITEMS_NWORKERS",
+    Int, get(
+        ENV, "RETESTITEMS_NWORKERS",
         string(min(ifelse(Sys.iswindows(), 0, Hwloc.num_physical_cores()), 4))
     )
 )
-const RETESTITEMS_NWORKER_THREADS = parse(Int,
+const RETESTITEMS_NWORKER_THREADS = parse(
+    Int,
     get(
         ENV, "RETESTITEMS_NWORKER_THREADS",
         string(max(Hwloc.num_virtual_cores() ÷ max(RETESTITEMS_NWORKERS, 1), 1))
@@ -25,8 +36,22 @@ const RETESTITEMS_NWORKER_THREADS = parse(Int,
 
 @info "Running tests for group: $(GROUP) with $(RETESTITEMS_NWORKERS) workers"
 
-ReTestItems.runtests(
-    NonlinearSolve; tags = (GROUP == "all" ? nothing : [Symbol(GROUP)]),
-    nworkers = RETESTITEMS_NWORKERS, nworker_threads = RETESTITEMS_NWORKER_THREADS,
-    testitem_timeout = 3600
-)
+if GROUP != "trim"
+    ReTestItems.runtests(
+        NonlinearSolve; tags = (GROUP == "all" ? nothing : [Symbol(GROUP)]),
+        nworkers = RETESTITEMS_NWORKERS, nworker_threads = RETESTITEMS_NWORKER_THREADS,
+        testitem_timeout = 3600
+    )
+elseif GROUP == "trim" && VERSION >= v"1.12.0-rc1"  # trimming has been introduced in julia 1.12
+    activate_trim_env!()
+    @safetestset "Clean implementation (non-trimmable)" begin
+        using SciMLBase: successful_retcode
+        include("trim/clean_optimization.jl")
+        @test successful_retcode(minimize(1.0).retcode)
+    end
+    @safetestset "Trimmable implementation" begin
+        using SciMLBase: successful_retcode
+        include("trim/trimmable_optimization.jl")
+        @test successful_retcode(minimize(1.0).retcode)
+    end
+end
diff --git a/test/trim/Project.toml b/test/trim/Project.toml
new file mode 100644
index 000000000..018357746
--- /dev/null
+++ b/test/trim/Project.toml
@@ -0,0 +1,27 @@
+[deps]
+ADTypes = "47edcb42-4c32-4615-8424-f2b9edc5f35b"
+DiffEqBase = "2b5f629d-d688-5b77-993f-72d75c75574e"
+ForwardDiff = "f6369f11-7733-5829-9624-2563aa707210"
+LinearAlgebra = "37e2e46d-f89d-539d-b4ee-838fcccc9c8e"
+LinearSolve = "7ed4a6bd-45f5-4d41-b270-4a48e9bafcae"
+NonlinearSolveFirstOrder = "5959db7a-ea39-4486-b5fe-2dd0bf03d60d"
+Polyester = "f517fe37-dbe3-4b94-8317-1923a5111588"
+PolyesterWeave = "1d0040c9-8b98-4ee7-8388-3f51789ca0ad"
+SafeTestsets = "1bc83da4-3b8d-516f-aca4-4fe02f6d838f"
+SciMLBase = "0bca4576-84f4-4d90-8ffe-ffa030f20462"
+StaticArrays = "90137ffa-7385-5640-81b9-e52037218182"
+
+[sources]
+ForwardDiff = {rev = "rv/remove-quote-assert-string-interpolation", url = "https://github.com/RomeoV/ForwardDiff.jl"}
+LinearSolve = {rev = "rv/remove-linsolve-forwarddiff-special-path", url = "https://github.com/RomeoV/LinearSolve.jl"}
+NonlinearSolveFirstOrder = {path = "../../lib/NonlinearSolveFirstOrder"}
+Polyester = {rev = "master", url = "https://github.com/RomeoV/Polyester.jl"}
+PolyesterWeave = {rev = "main", url = "https://github.com/RomeoV/PolyesterWeave.jl"}
+SciMLBase = {rev = "as/fix-jet-opt", url = "https://github.com/AayushSabharwal/SciMLBase.jl"}
+
+[compat]
+ADTypes = "1.15.0"
+DiffEqBase = "6.179.0"
+LinearAlgebra = "1.12.0"
+NonlinearSolveFirstOrder = "1.6.0"
+StaticArrays = "1.9.0"
diff --git a/test/trim/clean_optimization.jl b/test/trim/clean_optimization.jl
new file mode 100644
index 000000000..338fe3544
--- /dev/null
+++ b/test/trim/clean_optimization.jl
@@ -0,0 +1,32 @@
+using NonlinearSolveFirstOrder
+using ADTypes: AutoForwardDiff
+using ForwardDiff
+using LinearAlgebra
+using StaticArrays
+using LinearSolve
+const LS = LinearSolve
+
+function f(u, p)
+    L, U = cholesky(p.Σ)
+    rhs = (u .* u .- p.λ)
+    # there are some issues currently with LinearSolve and triangular matrices,
+    # so we just make `L` dense here.
+    linprob = LinearProblem(Matrix(L), rhs)
+    alg = LS.GenericLUFactorization()
+    sol = LinearSolve.solve(linprob, alg)
+    return sol.u
+end
+
+struct MyParams{T, M}
+    λ::T
+    Σ::M
+end
+
+function minimize(x)
+    autodiff = AutoForwardDiff(; chunksize=1)
+    alg = TrustRegion(; autodiff, linsolve=LS.CholeskyFactorization())
+    ps = MyParams(rand(), hermitianpart(rand(2,2)+2I))
+    prob = NonlinearLeastSquaresProblem{false}(f, rand(2), ps)
+    sol = solve(prob, alg)
+    return sol
+end
diff --git a/test/trim/trimmable_optimization.jl b/test/trim/trimmable_optimization.jl
new file mode 100644
index 000000000..51aa6ee72
--- /dev/null
+++ b/test/trim/trimmable_optimization.jl
@@ -0,0 +1,35 @@
+using NonlinearSolveFirstOrder
+using ADTypes: AutoForwardDiff
+using ForwardDiff
+using LinearAlgebra
+using StaticArrays
+using LinearSolve
+const LS = LinearSolve
+
+function f(u, p)
+    L, U = cholesky(p.Σ)
+    rhs = (u .* u .- p.λ)
+    # there are some issues currently with LinearSolve and triangular matrices,
+    # so we just make `L` dense here.
+    linprob = LinearProblem(Matrix(L), rhs)
+    alg = LS.GenericLUFactorization()
+    sol = LinearSolve.solve(linprob, alg)
+    return sol.u
+end
+
+struct MyParams{T, M}
+    λ::T
+    Σ::M
+end
+
+const autodiff = AutoForwardDiff(; chunksize = 1)
+const alg = TrustRegion(; autodiff, linsolve = LS.CholeskyFactorization())
+const prob = NonlinearLeastSquaresProblem{false}(f, rand(2), MyParams(rand(), hermitianpart(rand(2, 2) + 2I)))
+const cache = init(prob, alg)
+
+function minimize(x)
+    ps = MyParams(x, hermitianpart(rand(2, 2) + 2I))
+    reinit!(cache, rand(2); p = ps)
+    solve!(cache)
+    return cache
+end

From e728e55d2c07c57d5473820068399f167b01e65c Mon Sep 17 00:00:00 2001
From: Romeo Valentin <romeov@stanford.edu>
Date: Fri, 1 Aug 2025 15:38:49 -0700
Subject: [PATCH 02/19] Add JET tests for now

---
 test/runtests.jl                    | 5 +----
 test/trim/Project.toml              | 1 +
 test/trim/clean_optimization.jl     | 5 +++++
 test/trim/trimmable_optimization.jl | 5 +++++
 4 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/test/runtests.jl b/test/runtests.jl
index e1a928ae2..4ea08a2da 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -1,6 +1,4 @@
-using NonlinearSolve, Hwloc, InteractiveUtils, Pkg
-using SafeTestsets
-using ReTestItems
+using ReTestItems, NonlinearSolve, Hwloc, InteractiveUtils, Pkg
 
 @info sprint(InteractiveUtils.versioninfo)
 
@@ -8,7 +6,6 @@ const GROUP = lowercase(get(ENV, "GROUP", "All"))
 
 function activate_trim_env!()
     Pkg.activate(abspath(joinpath(dirname(@__FILE__), "trim")))
-    Pkg.develop(PackageSpec(path = dirname(@__DIR__)))
     Pkg.instantiate()
     return nothing
 end
diff --git a/test/trim/Project.toml b/test/trim/Project.toml
index 018357746..d0afc466c 100644
--- a/test/trim/Project.toml
+++ b/test/trim/Project.toml
@@ -2,6 +2,7 @@
 ADTypes = "47edcb42-4c32-4615-8424-f2b9edc5f35b"
 DiffEqBase = "2b5f629d-d688-5b77-993f-72d75c75574e"
 ForwardDiff = "f6369f11-7733-5829-9624-2563aa707210"
+JET = "c3a54625-cd67-489e-a8e7-0a5a0ff4e31b"
 LinearAlgebra = "37e2e46d-f89d-539d-b4ee-838fcccc9c8e"
 LinearSolve = "7ed4a6bd-45f5-4d41-b270-4a48e9bafcae"
 NonlinearSolveFirstOrder = "5959db7a-ea39-4486-b5fe-2dd0bf03d60d"
diff --git a/test/trim/clean_optimization.jl b/test/trim/clean_optimization.jl
index 338fe3544..b6f3875a1 100644
--- a/test/trim/clean_optimization.jl
+++ b/test/trim/clean_optimization.jl
@@ -5,6 +5,8 @@ using LinearAlgebra
 using StaticArrays
 using LinearSolve
 const LS = LinearSolve
+using SciMLBase: successful_retcode
+using JET
 
 function f(u, p)
     L, U = cholesky(p.Σ)
@@ -30,3 +32,6 @@ function minimize(x)
     sol = solve(prob, alg)
     return sol
 end
+
+@test successful_retcode(minimize(1.0).retcode)
+@test_opt minimize(1.0) broken=true
diff --git a/test/trim/trimmable_optimization.jl b/test/trim/trimmable_optimization.jl
index 51aa6ee72..9bdc12b33 100644
--- a/test/trim/trimmable_optimization.jl
+++ b/test/trim/trimmable_optimization.jl
@@ -5,6 +5,8 @@ using LinearAlgebra
 using StaticArrays
 using LinearSolve
 const LS = LinearSolve
+using SciMLBase: successful_retcode
+using JET
 
 function f(u, p)
     L, U = cholesky(p.Σ)
@@ -33,3 +35,6 @@ function minimize(x)
     solve!(cache)
     return cache
 end
+
+@test successful_retcode(minimize(1.0).retcode)
+@test_opt minimize(1.0) broken=true

From a6357dde29c79b4ad8dc177a7168b109892fb20b Mon Sep 17 00:00:00 2001
From: Romeo Valentin <romeov@stanford.edu>
Date: Fri, 1 Aug 2025 15:41:00 -0700
Subject: [PATCH 03/19] Move all the trimming tests into their own file

---
 test/runtests.jl | 11 +----------
 1 file changed, 1 insertion(+), 10 deletions(-)

diff --git a/test/runtests.jl b/test/runtests.jl
index 4ea08a2da..c4cdaaee7 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -41,14 +41,5 @@ if GROUP != "trim"
     )
 elseif GROUP == "trim" && VERSION >= v"1.12.0-rc1"  # trimming has been introduced in julia 1.12
     activate_trim_env!()
-    @safetestset "Clean implementation (non-trimmable)" begin
-        using SciMLBase: successful_retcode
-        include("trim/clean_optimization.jl")
-        @test successful_retcode(minimize(1.0).retcode)
-    end
-    @safetestset "Trimmable implementation" begin
-        using SciMLBase: successful_retcode
-        include("trim/trimmable_optimization.jl")
-        @test successful_retcode(minimize(1.0).retcode)
-    end
+    include("trim/runtests.jl")
 end

From a6c2ba34f32121bf2269acea405aaeafb25b113a Mon Sep 17 00:00:00 2001
From: Romeo Valentin <romeov@stanford.edu>
Date: Fri, 1 Aug 2025 15:42:10 -0700
Subject: [PATCH 04/19] Add comments to `Project.toml` explaining PRd repos.

---
 test/trim/Project.toml | 17 ++++++++++++-----
 1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/test/trim/Project.toml b/test/trim/Project.toml
index d0afc466c..09321c042 100644
--- a/test/trim/Project.toml
+++ b/test/trim/Project.toml
@@ -13,12 +13,19 @@ SciMLBase = "0bca4576-84f4-4d90-8ffe-ffa030f20462"
 StaticArrays = "90137ffa-7385-5640-81b9-e52037218182"
 
 [sources]
-ForwardDiff = {rev = "rv/remove-quote-assert-string-interpolation", url = "https://github.com/RomeoV/ForwardDiff.jl"}
-LinearSolve = {rev = "rv/remove-linsolve-forwarddiff-special-path", url = "https://github.com/RomeoV/LinearSolve.jl"}
+# Remove assert that triggers false positive for JET. Tracked at https://github.com/aviatesk/JET.jl/issues/736.
+ForwardDiff = {url = "https://github.com/RomeoV/ForwardDiff.jl", rev="rv/remove-quote-assert-string-interpolation"}
+# Remove special path code path for ForwarDiff of LinearSolve, which uses untrimmable `deepcopy`.
+# Use of `deepcopy` is tracked at https://github.com/SciML/LinearSolve.jl/issues/648.
+LinearSolve = {url = "https://github.com/RomeoV/LinearSolve.jl", rev="rv/remove-linsolve-forwarddiff-special-path"}
 NonlinearSolveFirstOrder = {path = "../../lib/NonlinearSolveFirstOrder"}
-Polyester = {rev = "master", url = "https://github.com/RomeoV/Polyester.jl"}
-PolyesterWeave = {rev = "main", url = "https://github.com/RomeoV/PolyesterWeave.jl"}
-SciMLBase = {rev = "as/fix-jet-opt", url = "https://github.com/AayushSabharwal/SciMLBase.jl"}
+# Remove use of CPUSummary which segfaults trimmed binary. Tracked at https://github.com/JuliaSIMD/Polyester.jl/pull/163.
+Polyester = {url = "https://github.com/RomeoV/Polyester.jl", rev="master"}
+# Remove use of CPUSummary which segfaults trimmed binary. Tracked at https://github.com/JuliaSIMD/PolyesterWeave.jl/pull/28
+PolyesterWeave = {url = "https://github.com/RomeoV/PolyesterWeave.jl", rev="main"}
+# Fix a type instability. Tracked at https://github.com/SciML/SciMLBase.jl/pull/1074.
+SciMLBase = {url = "https://github.com/AayushSabharwal/SciMLBase.jl", rev="as/fix-jet-opt"}
+
 
 [compat]
 ADTypes = "1.15.0"

From a5d4b8eec191b1e58b39eed45758252c706a125c Mon Sep 17 00:00:00 2001
From: Romeo Valentin <romeov@stanford.edu>
Date: Fri, 1 Aug 2025 15:42:52 -0700
Subject: [PATCH 05/19] fixup! Add JET tests for now

---
 test/trim/trimmable_optimization.jl | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/test/trim/trimmable_optimization.jl b/test/trim/trimmable_optimization.jl
index 9bdc12b33..ae46caa19 100644
--- a/test/trim/trimmable_optimization.jl
+++ b/test/trim/trimmable_optimization.jl
@@ -37,4 +37,4 @@ function minimize(x)
 end
 
 @test successful_retcode(minimize(1.0).retcode)
-@test_opt minimize(1.0) broken=true
+@test_opt minimize(1.0)

From 7462b077dbd4ba42abe367c8b0e3639ba1698a7b Mon Sep 17 00:00:00 2001
From: Romeo Valentin <romeov@stanford.edu>
Date: Fri, 1 Aug 2025 15:51:43 -0700
Subject: [PATCH 06/19] Fix JET tests

---
 test/trim/clean_optimization.jl     | 2 +-
 test/trim/trimmable_optimization.jl | 2 ++
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/test/trim/clean_optimization.jl b/test/trim/clean_optimization.jl
index b6f3875a1..62d4c5303 100644
--- a/test/trim/clean_optimization.jl
+++ b/test/trim/clean_optimization.jl
@@ -34,4 +34,4 @@ function minimize(x)
 end
 
 @test successful_retcode(minimize(1.0).retcode)
-@test_opt minimize(1.0) broken=true
+@test_opt minimize(1.0)
diff --git a/test/trim/trimmable_optimization.jl b/test/trim/trimmable_optimization.jl
index ae46caa19..3ff388fdc 100644
--- a/test/trim/trimmable_optimization.jl
+++ b/test/trim/trimmable_optimization.jl
@@ -1,5 +1,6 @@
 using NonlinearSolveFirstOrder
 using ADTypes: AutoForwardDiff
+using DiffEqBase
 using ForwardDiff
 using LinearAlgebra
 using StaticArrays
@@ -23,6 +24,7 @@ struct MyParams{T, M}
     λ::T
     Σ::M
 end
+DiffEqBase.anyeltypedual(::MyParams) = Any
 
 const autodiff = AutoForwardDiff(; chunksize = 1)
 const alg = TrustRegion(; autodiff, linsolve = LS.CholeskyFactorization())

From 360da41bf8bf4dda455064956c34d26312ec865c Mon Sep 17 00:00:00 2001
From: Romeo Valentin <romeov@stanford.edu>
Date: Fri, 1 Aug 2025 16:22:49 -0700
Subject: [PATCH 07/19] refactor: main runtests.jl file

---
 test/runtests.jl | 49 +++++++++++++++++++++++-------------------------
 1 file changed, 23 insertions(+), 26 deletions(-)

diff --git a/test/runtests.jl b/test/runtests.jl
index c4cdaaee7..3f187a9db 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -1,45 +1,42 @@
-using ReTestItems, NonlinearSolve, Hwloc, InteractiveUtils, Pkg
+using ReTestItems, Hwloc, InteractiveUtils, Pkg
 
 @info sprint(InteractiveUtils.versioninfo)
 
 const GROUP = lowercase(get(ENV, "GROUP", "All"))
 
-function activate_trim_env!()
-    Pkg.activate(abspath(joinpath(dirname(@__FILE__), "trim")))
-    Pkg.instantiate()
-    return nothing
-end
+if GROUP != "trim"
+    using NonlinearSolve  # trimming uses a NonlinearSolve from a custom environment
 
-const EXTRA_PKGS = Pkg.PackageSpec[]
-if GROUP == "all" || GROUP == "downstream"
-    push!(EXTRA_PKGS, Pkg.PackageSpec("ModelingToolkit"))
-    push!(EXTRA_PKGS, Pkg.PackageSpec("SymbolicIndexingInterface"))
-end
-length(EXTRA_PKGS) ≥ 1 && Pkg.add(EXTRA_PKGS)
+    const EXTRA_PKGS = Pkg.PackageSpec[]
+    if GROUP == "all" || GROUP == "downstream"
+        push!(EXTRA_PKGS, Pkg.PackageSpec("ModelingToolkit"))
+        push!(EXTRA_PKGS, Pkg.PackageSpec("SymbolicIndexingInterface"))
+    end
+    length(EXTRA_PKGS) ≥ 1 && Pkg.add(EXTRA_PKGS)
 
-const RETESTITEMS_NWORKERS = parse(
-    Int, get(
-        ENV, "RETESTITEMS_NWORKERS",
-        string(min(ifelse(Sys.iswindows(), 0, Hwloc.num_physical_cores()), 4))
+    const RETESTITEMS_NWORKERS = parse(
+        Int, get(
+            ENV, "RETESTITEMS_NWORKERS",
+            string(min(ifelse(Sys.iswindows(), 0, Hwloc.num_physical_cores()), 4))
+        )
     )
-)
-const RETESTITEMS_NWORKER_THREADS = parse(
-    Int,
-    get(
-        ENV, "RETESTITEMS_NWORKER_THREADS",
-        string(max(Hwloc.num_virtual_cores() ÷ max(RETESTITEMS_NWORKERS, 1), 1))
+    const RETESTITEMS_NWORKER_THREADS = parse(
+        Int,
+        get(
+            ENV, "RETESTITEMS_NWORKER_THREADS",
+            string(max(Hwloc.num_virtual_cores() ÷ max(RETESTITEMS_NWORKERS, 1), 1))
+        )
     )
-)
 
-@info "Running tests for group: $(GROUP) with $(RETESTITEMS_NWORKERS) workers"
+    @info "Running tests for group: $(GROUP) with $(RETESTITEMS_NWORKERS) workers"
 
-if GROUP != "trim"
     ReTestItems.runtests(
         NonlinearSolve; tags = (GROUP == "all" ? nothing : [Symbol(GROUP)]),
         nworkers = RETESTITEMS_NWORKERS, nworker_threads = RETESTITEMS_NWORKER_THREADS,
         testitem_timeout = 3600
     )
 elseif GROUP == "trim" && VERSION >= v"1.12.0-rc1"  # trimming has been introduced in julia 1.12
-    activate_trim_env!()
+    Pkg.activate(joinpath(dirname(@__FILE__), "trim"))
+    Pkg.instantiate()
     include("trim/runtests.jl")
 end

From c23f977db9d7b9636d488d07940c7b736141e067 Mon Sep 17 00:00:00 2001
From: Romeo Valentin <romeov@stanford.edu>
Date: Fri, 1 Aug 2025 16:23:10 -0700
Subject: [PATCH 08/19] Add compat entries

---
 test/trim/Project.toml | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/test/trim/Project.toml b/test/trim/Project.toml
index 09321c042..c19f8ac65 100644
--- a/test/trim/Project.toml
+++ b/test/trim/Project.toml
@@ -30,6 +30,9 @@ SciMLBase = {url = "https://github.com/AayushSabharwal/SciMLBase.jl", rev="as/fi
 [compat]
 ADTypes = "1.15.0"
 DiffEqBase = "6.179.0"
+ForwardDiff = "1.0.1"
 LinearAlgebra = "1.12.0"
 NonlinearSolveFirstOrder = "1.6.0"
+Polyester = "0.7.18"
+PolyesterWeave = "0.2.2"
 StaticArrays = "1.9.0"

From 69b54a1bdb771fbd4dd4cfcc3184841cd082a04d Mon Sep 17 00:00:00 2001
From: Romeo Valentin <romeov@stanford.edu>
Date: Fri, 1 Aug 2025 16:24:18 -0700
Subject: [PATCH 09/19] fixup! Start implementing trimming test

---
 Project.toml | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/Project.toml b/Project.toml
index a8dbaa9f6..49a32dc64 100644
--- a/Project.toml
+++ b/Project.toml
@@ -143,7 +143,6 @@ PolyesterForwardDiff = "98d1487c-24ca-40b6-b7ab-df2af84e126b"
 Random = "9a3f8284-a2c9-5f02-9a11-845980a1fd5c"
 ReTestItems = "817f1d60-ba6b-4fd5-9520-3cf149f6a823"
 SIAMFANLEquations = "084e46ad-d928-497d-ad5e-07fa361a48c4"
-SafeTestsets = "1bc83da4-3b8d-516f-aca4-4fe02f6d838f"
 SparseConnectivityTracer = "9f842d2f-2579-4b1d-911e-f412cf18a3f5"
 SpeedMapping = "f1835b91-879b-4a3f-a438-e4baacf14412"
 StableRNGs = "860ef19b-820b-49d6-a774-d7a799459cd3"
@@ -171,4 +170,4 @@ path = "lib/NonlinearSolveSpectralMethods"
 path = "lib/SimpleNonlinearSolve"
 
 [targets]
-test = ["Aqua", "BandedMatrices", "BenchmarkTools", "CUDA", "Enzyme", "ExplicitImports", "FastLevenbergMarquardt", "FixedPointAcceleration", "Hwloc", "InteractiveUtils", "LeastSquaresOptim", "LineSearches", "MINPACK", "NLSolvers", "NLsolve", "NaNMath", "NonlinearProblemLibrary", "OrdinaryDiffEqTsit5", "PETSc", "Pkg", "PolyesterForwardDiff", "Random", "ReTestItems", "SafeTestsets", "SIAMFANLEquations", "SparseConnectivityTracer", "SpeedMapping", "StableRNGs", "StaticArrays", "Sundials", "Test", "Zygote"]
+test = ["Aqua", "BandedMatrices", "BenchmarkTools", "CUDA", "Enzyme", "ExplicitImports", "FastLevenbergMarquardt", "FixedPointAcceleration", "Hwloc", "InteractiveUtils", "LeastSquaresOptim", "LineSearches", "MINPACK", "NLSolvers", "NLsolve", "NaNMath", "NonlinearProblemLibrary", "OrdinaryDiffEqTsit5", "PETSc", "Pkg", "PolyesterForwardDiff", "Random", "ReTestItems", "SIAMFANLEquations", "SparseConnectivityTracer", "SpeedMapping", "StableRNGs", "StaticArrays", "Sundials", "Test", "Zygote"]

From 8c45ab348bfc4bc4de9b5984db7e54fe6905c9c2 Mon Sep 17 00:00:00 2001
From: Romeo Valentin <romeov@stanford.edu>
Date: Fri, 1 Aug 2025 18:38:00 -0700
Subject: [PATCH 10/19] Add trimming test

---
 test/trim/main.jl         | 12 ++++++++
 test/trim/runtests.jl     | 65 +++++++++++++++++++++++++++++++++++++++
 test/trim/src/TrimTest.jl |  3 ++
 3 files changed, 80 insertions(+)
 create mode 100644 test/trim/main.jl
 create mode 100644 test/trim/runtests.jl
 create mode 100644 test/trim/src/TrimTest.jl

diff --git a/test/trim/main.jl b/test/trim/main.jl
new file mode 100644
index 000000000..dd85aca84
--- /dev/null
+++ b/test/trim/main.jl
@@ -0,0 +1,12 @@
+using TrimTest
+
+function (@main)(argv::Vector{String})::Cint
+    λ = try
+        parse(Float64, argv[2])
+    catch
+        parse(Float64, argv[1])
+    end
+    sol = TrimTest.minimize(λ)
+    println(Core.stdout, sum(sol.u))
+    return 0
+end
diff --git a/test/trim/runtests.jl b/test/trim/runtests.jl
new file mode 100644
index 000000000..2ef26457a
--- /dev/null
+++ b/test/trim/runtests.jl
@@ -0,0 +1,65 @@
+using SafeTestsets
+
+@safetestset "Clean implementation (non-trimmable)" begin
+    using JET
+    using SciMLBase: successful_retcode
+    include("clean_optimization.jl")
+    @test successful_retcode(minimize(1.0).retcode)
+    # can't use `@test_opt` macro here because it would eval before `using JET`
+    # is processed
+    test_opt(minimize, (typeof(1.0),))
+end
+
+@safetestset "Trimmable implementation" begin
+    using JET
+    using SciMLBase: successful_retcode
+    include("trimmable_optimization.jl")
+    @test successful_retcode(minimize(1.0).retcode)
+    # can't use `@test_opt` macro here because it would eval before `using JET`
+    # is processed
+    test_opt(minimize, (typeof(1.0),))
+end
+
+@safetestset "Run trim" begin
+    # https://discourse.julialang.org/t/capture-stdout-and-stderr-in-case-a-command-fails/101772/3?u=romeov
+    "Run a Cmd object, returning the stdout & stderr contents plus the exit code"
+    function _execute(cmd::Cmd)
+        out = Pipe()
+        err = Pipe()
+        process = run(pipeline(ignorestatus(cmd); stdout = out, stderr = err))
+        close(out.in)
+        close(err.in)
+        out = (
+            stdout = String(read(out)), stderr = String(read(err)),
+            exitcode = process.exitcode,
+        )
+        return out
+    end
+
+    JULIAC = normpath(
+        joinpath(
+            Sys.BINDIR, Base.DATAROOTDIR, "julia", "juliac",
+            "juliac.jl"
+        )
+    )
+    @test isfile(JULIAC)
+    binpath = tempname()
+    cmd = `$(Base.julia_cmd()) --project=. --depwarn=error $(JULIAC) --experimental --trim=unsafe-warn --output-exe $(binpath) main.jl`
+
+    # since we are calling Julia from Julia, we first need to clean some
+    # environment variables
+    clean_env = copy(ENV)
+    delete!(clean_env, "JULIA_PROJECT")
+    delete!(clean_env, "JULIA_LOAD_PATH")
+    # We could just check for success, but then failures are hard to debug.
+    # Instead we use `_execute` to also capture `stdout` and `stderr`.
+    # @test success(setenv(cmd, clean_env))
+    trimcall = _execute(setenv(cmd, clean_env; dir = @__DIR__))
+    if trimcall.exitcode != 0
+        @show trimcall.stdout
+        @show trimcall.stderr
+    end
+    @test trimcall.exitcode == 0
+    @test isfile(binpath)
+    @test success(`$(binpath) 1.0`)
+end
diff --git a/test/trim/src/TrimTest.jl b/test/trim/src/TrimTest.jl
new file mode 100644
index 000000000..6862439be
--- /dev/null
+++ b/test/trim/src/TrimTest.jl
@@ -0,0 +1,3 @@
+module TrimTest
+include("../trimmable_optimization.jl")
+end

From bd68b9d6da163a28171cfc3881b0a2ac396a6d3c Mon Sep 17 00:00:00 2001
From: Romeo Valentin <romeov@stanford.edu>
Date: Fri, 1 Aug 2025 18:52:07 -0700
Subject: [PATCH 11/19] Put trimmable code into package

See TrimTest.jl comment for rationale.
---
 test/trim/Project.toml              |  3 +++
 test/trim/clean_optimization.jl     |  5 -----
 test/trim/main.jl                   |  6 +-----
 test/trim/src/TrimTest.jl           | 23 +++++++++++++++++++++++
 test/trim/trimmable_optimization.jl |  9 ++-------
 5 files changed, 29 insertions(+), 17 deletions(-)

diff --git a/test/trim/Project.toml b/test/trim/Project.toml
index c19f8ac65..88a8ac1b3 100644
--- a/test/trim/Project.toml
+++ b/test/trim/Project.toml
@@ -1,3 +1,6 @@
+name = "TrimTest"
+uuid = "7e54ada7-ece5-4046-aa01-512d530850d8"
+
 [deps]
 ADTypes = "47edcb42-4c32-4615-8424-f2b9edc5f35b"
 DiffEqBase = "2b5f629d-d688-5b77-993f-72d75c75574e"
diff --git a/test/trim/clean_optimization.jl b/test/trim/clean_optimization.jl
index 62d4c5303..338fe3544 100644
--- a/test/trim/clean_optimization.jl
+++ b/test/trim/clean_optimization.jl
@@ -5,8 +5,6 @@ using LinearAlgebra
 using StaticArrays
 using LinearSolve
 const LS = LinearSolve
-using SciMLBase: successful_retcode
-using JET
 
 function f(u, p)
     L, U = cholesky(p.Σ)
@@ -32,6 +30,3 @@ function minimize(x)
     sol = solve(prob, alg)
     return sol
 end
-
-@test successful_retcode(minimize(1.0).retcode)
-@test_opt minimize(1.0)
diff --git a/test/trim/main.jl b/test/trim/main.jl
index dd85aca84..4c3c27377 100644
--- a/test/trim/main.jl
+++ b/test/trim/main.jl
@@ -1,11 +1,7 @@
 using TrimTest
 
 function (@main)(argv::Vector{String})::Cint
-    λ = try
-        parse(Float64, argv[2])
-    catch
-        parse(Float64, argv[1])
-    end
+    λ = parse(Float64, argv[2])
     sol = TrimTest.minimize(λ)
     println(Core.stdout, sum(sol.u))
     return 0
diff --git a/test/trim/src/TrimTest.jl b/test/trim/src/TrimTest.jl
index 6862439be..f1955c4c2 100644
--- a/test/trim/src/TrimTest.jl
+++ b/test/trim/src/TrimTest.jl
@@ -1,3 +1,26 @@
 module TrimTest
+#=
+Currently, trimming only works if the target code is in a package. I.e., trying to trim
+```julia
+include("trimmable_optimization.jl")
+function (@main)(argv::Vector{String})::Cint
+    minimize(1.0)
+    return 0
+end
+```
+or even
+```julia
+mod MyMod
+    include("trimmable_optimization.jl")
+end
+function (@main)(argv::Vector{String})::Cint
+    MyMod.minimize(1.0)
+    return 0
+end
+```
+segfaults `juliac`. Looking at the segfault stacktrace it seems the culprit is
+`const cache = init(...)`. Either way, we circumvent the segfault by putting
+this below code into a package definition.
+=#
 include("../trimmable_optimization.jl")
 end
diff --git a/test/trim/trimmable_optimization.jl b/test/trim/trimmable_optimization.jl
index 3ff388fdc..5a7b7641b 100644
--- a/test/trim/trimmable_optimization.jl
+++ b/test/trim/trimmable_optimization.jl
@@ -1,13 +1,12 @@
 using NonlinearSolveFirstOrder
-using ADTypes: AutoForwardDiff
 using DiffEqBase
+using ADTypes: AutoForwardDiff
 using ForwardDiff
 using LinearAlgebra
 using StaticArrays
 using LinearSolve
+import SciMLBase
 const LS = LinearSolve
-using SciMLBase: successful_retcode
-using JET
 
 function f(u, p)
     L, U = cholesky(p.Σ)
@@ -24,7 +23,6 @@ struct MyParams{T, M}
     λ::T
     Σ::M
 end
-DiffEqBase.anyeltypedual(::MyParams) = Any
 
 const autodiff = AutoForwardDiff(; chunksize = 1)
 const alg = TrustRegion(; autodiff, linsolve = LS.CholeskyFactorization())
@@ -37,6 +35,3 @@ function minimize(x)
     solve!(cache)
     return cache
 end
-
-@test successful_retcode(minimize(1.0).retcode)
-@test_opt minimize(1.0)

From 1fc1c1881a3181db0a36ebdbd85836f10aa9856c Mon Sep 17 00:00:00 2001
From: Romeo Valentin <romeov@stanford.edu>
Date: Fri, 1 Aug 2025 19:02:50 -0700
Subject: [PATCH 12/19] nit: grammar

---
 test/runtests.jl | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/test/runtests.jl b/test/runtests.jl
index 3f187a9db..997d87b0a 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -5,7 +5,7 @@ using ReTestItems, Hwloc, InteractiveUtils, Pkg
 const GROUP = lowercase(get(ENV, "GROUP", "All"))
 
 if GROUP != "trim"
-    using NonlinearSolve  # trimming uses a NonlinearSolve from a custom environment
+    using NonlinearSolve  # trimming uses NonlinearSolve from a custom environment
 
     const EXTRA_PKGS = Pkg.PackageSpec[]
     if GROUP == "all" || GROUP == "downstream"

From 8ec2de04fe724258aed0994f3c1d4f36c2b647e0 Mon Sep 17 00:00:00 2001
From: Romeo Valentin <romeov@stanford.edu>
Date: Fri, 1 Aug 2025 19:08:40 -0700
Subject: [PATCH 13/19] Add "trim" group to CI

---
 .github/workflows/CI_NonlinearSolve.yml | 1 +
 1 file changed, 1 insertion(+)

diff --git a/.github/workflows/CI_NonlinearSolve.yml b/.github/workflows/CI_NonlinearSolve.yml
index 84aa7a2ba..0a137a8ac 100644
--- a/.github/workflows/CI_NonlinearSolve.yml
+++ b/.github/workflows/CI_NonlinearSolve.yml
@@ -36,6 +36,7 @@ jobs:
           - downstream
           - wrappers
           - misc
+          - trim
         version:
           - "1"
           - "lts"

From 076b9f0868351c557031b346959069b9a5a08671 Mon Sep 17 00:00:00 2001
From: Romeo Valentin <romeov@stanford.edu>
Date: Fri, 1 Aug 2025 19:21:11 -0700
Subject: [PATCH 14/19] Add test that `optimization_clean` doesn't trim, marked
 `broken`

---
 test/trim/{main.jl => main_clean.jl}          |  2 +-
 test/trim/main_trimmable.jl                   |  8 +++
 ..._optimization.jl => optimization_clean.jl} |  8 ++-
 ...imization.jl => optimization_trimmable.jl} |  2 +
 test/trim/runtests.jl                         | 58 ++++++++++---------
 test/trim/src/TrimTest.jl                     |  7 ++-
 6 files changed, 51 insertions(+), 34 deletions(-)
 rename test/trim/{main.jl => main_clean.jl} (75%)
 create mode 100644 test/trim/main_trimmable.jl
 rename test/trim/{clean_optimization.jl => optimization_clean.jl} (76%)
 rename test/trim/{trimmable_optimization.jl => optimization_trimmable.jl} (96%)

diff --git a/test/trim/main.jl b/test/trim/main_clean.jl
similarity index 75%
rename from test/trim/main.jl
rename to test/trim/main_clean.jl
index 4c3c27377..be60b697a 100644
--- a/test/trim/main.jl
+++ b/test/trim/main_clean.jl
@@ -2,7 +2,7 @@ using TrimTest
 
 function (@main)(argv::Vector{String})::Cint
     λ = parse(Float64, argv[2])
-    sol = TrimTest.minimize(λ)
+    sol = TrimTest.TestModuleClean.minimize(λ)
     println(Core.stdout, sum(sol.u))
     return 0
 end
diff --git a/test/trim/main_trimmable.jl b/test/trim/main_trimmable.jl
new file mode 100644
index 000000000..b25e20fe0
--- /dev/null
+++ b/test/trim/main_trimmable.jl
@@ -0,0 +1,8 @@
+using TrimTest
+
+function (@main)(argv::Vector{String})::Cint
+    λ = parse(Float64, argv[2])
+    sol = TrimTest.TestModuleTrimmable.minimize(λ)
+    println(Core.stdout, sum(sol.u))
+    return 0
+end
diff --git a/test/trim/clean_optimization.jl b/test/trim/optimization_clean.jl
similarity index 76%
rename from test/trim/clean_optimization.jl
rename to test/trim/optimization_clean.jl
index 338fe3544..ca6de20e3 100644
--- a/test/trim/clean_optimization.jl
+++ b/test/trim/optimization_clean.jl
@@ -1,3 +1,4 @@
+module TestModuleClean
 using NonlinearSolveFirstOrder
 using ADTypes: AutoForwardDiff
 using ForwardDiff
@@ -23,10 +24,11 @@ struct MyParams{T, M}
 end
 
 function minimize(x)
-    autodiff = AutoForwardDiff(; chunksize=1)
-    alg = TrustRegion(; autodiff, linsolve=LS.CholeskyFactorization())
-    ps = MyParams(rand(), hermitianpart(rand(2,2)+2I))
+    autodiff = AutoForwardDiff(; chunksize = 1)
+    alg = TrustRegion(; autodiff, linsolve = LS.CholeskyFactorization())
+    ps = MyParams(rand(), hermitianpart(rand(2, 2) + 2I))
     prob = NonlinearLeastSquaresProblem{false}(f, rand(2), ps)
     sol = solve(prob, alg)
     return sol
 end
+end
diff --git a/test/trim/trimmable_optimization.jl b/test/trim/optimization_trimmable.jl
similarity index 96%
rename from test/trim/trimmable_optimization.jl
rename to test/trim/optimization_trimmable.jl
index 5a7b7641b..c651d7329 100644
--- a/test/trim/trimmable_optimization.jl
+++ b/test/trim/optimization_trimmable.jl
@@ -1,3 +1,4 @@
+module TestModuleTrimmable
 using NonlinearSolveFirstOrder
 using DiffEqBase
 using ADTypes: AutoForwardDiff
@@ -35,3 +36,4 @@ function minimize(x)
     solve!(cache)
     return cache
 end
+end
diff --git a/test/trim/runtests.jl b/test/trim/runtests.jl
index 2ef26457a..8146b2468 100644
--- a/test/trim/runtests.jl
+++ b/test/trim/runtests.jl
@@ -3,21 +3,21 @@ using SafeTestsets
 @safetestset "Clean implementation (non-trimmable)" begin
     using JET
     using SciMLBase: successful_retcode
-    include("clean_optimization.jl")
-    @test successful_retcode(minimize(1.0).retcode)
-    # can't use `@test_opt` macro here because it would eval before `using JET`
-    # is processed
-    test_opt(minimize, (typeof(1.0),))
+    include("optimization_clean.jl")
+    @test successful_retcode(TestModuleClean.minimize(1.0).retcode)
+    # can't use `@test_opt` macro here because it would try to eval before
+    # `using JET` is processed
+    test_opt(TestModuleClean.minimize, (typeof(1.0),))
 end
 
 @safetestset "Trimmable implementation" begin
     using JET
     using SciMLBase: successful_retcode
-    include("trimmable_optimization.jl")
-    @test successful_retcode(minimize(1.0).retcode)
-    # can't use `@test_opt` macro here because it would eval before `using JET`
-    # is processed
-    test_opt(minimize, (typeof(1.0),))
+    include("optimization_trimmable.jl")
+    @test successful_retcode(TestModuleClean.minimize(1.0).retcode)
+    # can't use `@test_opt` macro here because it would try to eval before
+    # `using JET` is processed
+    test_opt(TestModuleTrimmable.minimize, (typeof(1.0),))
 end
 
 @safetestset "Run trim" begin
@@ -43,23 +43,27 @@ end
         )
     )
     @test isfile(JULIAC)
-    binpath = tempname()
-    cmd = `$(Base.julia_cmd()) --project=. --depwarn=error $(JULIAC) --experimental --trim=unsafe-warn --output-exe $(binpath) main.jl`
 
-    # since we are calling Julia from Julia, we first need to clean some
-    # environment variables
-    clean_env = copy(ENV)
-    delete!(clean_env, "JULIA_PROJECT")
-    delete!(clean_env, "JULIA_LOAD_PATH")
-    # We could just check for success, but then failures are hard to debug.
-    # Instead we use `_execute` to also capture `stdout` and `stderr`.
-    # @test success(setenv(cmd, clean_env))
-    trimcall = _execute(setenv(cmd, clean_env; dir = @__DIR__))
-    if trimcall.exitcode != 0
-        @show trimcall.stdout
-        @show trimcall.stderr
+    for (mainfile, shouldpass) in [("main_trimmable.jl", true),
+                                   ("main_clean.jl", false)]
+        binpath = tempname()
+        cmd = `$(Base.julia_cmd()) --project=. --depwarn=error $(JULIAC) --experimental --trim=unsafe-warn --output-exe $(binpath) $(mainfile)`
+
+        # since we are calling Julia from Julia, we first need to clean some
+        # environment variables
+        clean_env = copy(ENV)
+        delete!(clean_env, "JULIA_PROJECT")
+        delete!(clean_env, "JULIA_LOAD_PATH")
+        # We could just check for success, but then failures are hard to debug.
+        # Instead we use `_execute` to also capture `stdout` and `stderr`.
+        # @test success(setenv(cmd, clean_env))
+        trimcall = _execute(setenv(cmd, clean_env; dir = @__DIR__))
+        if trimcall.exitcode != 0 && shouldpass
+            @show trimcall.stdout
+            @show trimcall.stderr
+        end
+        @test trimcall.exitcode == 0 broken=!shouldpass
+        @test isfile(binpath) broken=!shouldpass
+        @test success(`$(binpath) 1.0`) broken=!shouldpass
     end
-    @test trimcall.exitcode == 0
-    @test isfile(binpath)
-    @test success(`$(binpath) 1.0`)
 end
diff --git a/test/trim/src/TrimTest.jl b/test/trim/src/TrimTest.jl
index f1955c4c2..85d0f78fe 100644
--- a/test/trim/src/TrimTest.jl
+++ b/test/trim/src/TrimTest.jl
@@ -2,7 +2,7 @@ module TrimTest
 #=
 Currently, trimming only works if the target code is in a package. I.e., trying to trim
 ```julia
-include("trimmable_optimization.jl")
+include("optimization_trimmable.jl")
 function (@main)(argv::Vector{String})::Cint
     minimize(1.0)
     return 0
@@ -11,7 +11,7 @@ end
 or even
 ```julia
 mod MyMod
-    include("trimmable_optimization.jl")
+    include("optimization_trimmable.jl")
 end
 function (@main)(argv::Vector{String})::Cint
     MyMod.minimize(1.0)
@@ -22,5 +22,6 @@ segfaults `juliac`. Looking at the segfault stacktrace it seems the culprit is
 `const cache = init(...)`. Either way, we circumvent the segfault by putting
 this below code into a package definition.
 =#
-include("../trimmable_optimization.jl")
+include("../optimization_trimmable.jl")
+include("../optimization_clean.jl")
 end

From ff3ef269b325b0872fede84ad16c0e463f044122 Mon Sep 17 00:00:00 2001
From: Romeo Valentin <romeov@stanford.edu>
Date: Fri, 1 Aug 2025 19:24:29 -0700
Subject: [PATCH 15/19] fixup! Add test that `optimization_clean` doesn't trim,
 marked `broken`

---
 test/trim/runtests.jl | 16 +++++++++-------
 1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/test/trim/runtests.jl b/test/trim/runtests.jl
index 8146b2468..79c3d3b7c 100644
--- a/test/trim/runtests.jl
+++ b/test/trim/runtests.jl
@@ -14,7 +14,7 @@ end
     using JET
     using SciMLBase: successful_retcode
     include("optimization_trimmable.jl")
-    @test successful_retcode(TestModuleClean.minimize(1.0).retcode)
+    @test successful_retcode(TestModuleTrimmable.minimize(1.0).retcode)
     # can't use `@test_opt` macro here because it would try to eval before
     # `using JET` is processed
     test_opt(TestModuleTrimmable.minimize, (typeof(1.0),))
@@ -44,8 +44,10 @@ end
     )
     @test isfile(JULIAC)
 
-    for (mainfile, shouldpass) in [("main_trimmable.jl", true),
-                                   ("main_clean.jl", false)]
+    for (mainfile, expectedtopass) in [
+            ("main_trimmable.jl", true),
+            ("main_clean.jl", false),
+        ]
         binpath = tempname()
         cmd = `$(Base.julia_cmd()) --project=. --depwarn=error $(JULIAC) --experimental --trim=unsafe-warn --output-exe $(binpath) $(mainfile)`
 
@@ -58,12 +60,12 @@ end
         # Instead we use `_execute` to also capture `stdout` and `stderr`.
         # @test success(setenv(cmd, clean_env))
         trimcall = _execute(setenv(cmd, clean_env; dir = @__DIR__))
-        if trimcall.exitcode != 0 && shouldpass
+        if trimcall.exitcode != 0 && expectedtopass
             @show trimcall.stdout
             @show trimcall.stderr
         end
-        @test trimcall.exitcode == 0 broken=!shouldpass
-        @test isfile(binpath) broken=!shouldpass
-        @test success(`$(binpath) 1.0`) broken=!shouldpass
+        @test trimcall.exitcode == 0 broken = !expectedtopass
+        @test isfile(binpath) broken = !expectedtopass
+        @test success(`$(binpath) 1.0`) broken = !expectedtopass
     end
 end

From 4bd419c8f10cf6f0333d3c741e12bd2e7aeac8b1 Mon Sep 17 00:00:00 2001
From: Romeo Valentin <romeov@stanford.edu>
Date: Fri, 1 Aug 2025 19:50:02 -0700
Subject: [PATCH 16/19] Unfortunately, broken test also hangs. So comment out.

The rational in code comment.
---
 test/trim/runtests.jl | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/test/trim/runtests.jl b/test/trim/runtests.jl
index 79c3d3b7c..3810b2dd4 100644
--- a/test/trim/runtests.jl
+++ b/test/trim/runtests.jl
@@ -46,7 +46,11 @@ end
 
     for (mainfile, expectedtopass) in [
             ("main_trimmable.jl", true),
-            ("main_clean.jl", false),
+            #= The test below should verify that we indeed can't get a trimmed binary
+            # for the "clean" implementation, but will trigger in the future if
+            # it does start working. Unfortunately, right now it hangs indefinitely
+            # so we are commenting it out. =#
+            # ("main_clean.jl", false),
         ]
         binpath = tempname()
         cmd = `$(Base.julia_cmd()) --project=. --depwarn=error $(JULIAC) --experimental --trim=unsafe-warn --output-exe $(binpath) $(mainfile)`

From 3c332634bbac591aabadaedf2397b1d8f2304509 Mon Sep 17 00:00:00 2001
From: Romeo Valentin <romeov@stanford.edu>
Date: Sat, 2 Aug 2025 16:24:20 -0700
Subject: [PATCH 17/19] Appease JuliaFormatter

---
 test/trim/optimization_trimmable.jl |  6 +++++-
 test/trim/runtests.jl               | 26 ++++++++++++++------------
 2 files changed, 19 insertions(+), 13 deletions(-)

diff --git a/test/trim/optimization_trimmable.jl b/test/trim/optimization_trimmable.jl
index c651d7329..e1ee111d7 100644
--- a/test/trim/optimization_trimmable.jl
+++ b/test/trim/optimization_trimmable.jl
@@ -27,7 +27,11 @@ end
 
 const autodiff = AutoForwardDiff(; chunksize = 1)
 const alg = TrustRegion(; autodiff, linsolve = LS.CholeskyFactorization())
-const prob = NonlinearLeastSquaresProblem{false}(f, rand(2), MyParams(rand(), hermitianpart(rand(2, 2) + 2I)))
+const prob = NonlinearLeastSquaresProblem{false}(
+    f,
+    rand(2),
+    MyParams(rand(), hermitianpart(rand(2, 2) + 2I))
+)
 const cache = init(prob, alg)
 
 function minimize(x)
diff --git a/test/trim/runtests.jl b/test/trim/runtests.jl
index 3810b2dd4..a53aa77e0 100644
--- a/test/trim/runtests.jl
+++ b/test/trim/runtests.jl
@@ -22,7 +22,9 @@ end
 
 @safetestset "Run trim" begin
     # https://discourse.julialang.org/t/capture-stdout-and-stderr-in-case-a-command-fails/101772/3?u=romeov
-    "Run a Cmd object, returning the stdout & stderr contents plus the exit code"
+    """
+    Run a Cmd object, returning the stdout & stderr contents plus the exit code
+    """
     function _execute(cmd::Cmd)
         out = Pipe()
         err = Pipe()
@@ -31,27 +33,27 @@ end
         close(err.in)
         out = (
             stdout = String(read(out)), stderr = String(read(err)),
-            exitcode = process.exitcode,
+            exitcode = process.exitcode
         )
         return out
     end
 
     JULIAC = normpath(
         joinpath(
-            Sys.BINDIR, Base.DATAROOTDIR, "julia", "juliac",
-            "juliac.jl"
-        )
+        Sys.BINDIR, Base.DATAROOTDIR, "julia", "juliac",
+        "juliac.jl"
+    )
     )
     @test isfile(JULIAC)
 
     for (mainfile, expectedtopass) in [
-            ("main_trimmable.jl", true),
-            #= The test below should verify that we indeed can't get a trimmed binary
-            # for the "clean" implementation, but will trigger in the future if
-            # it does start working. Unfortunately, right now it hangs indefinitely
-            # so we are commenting it out. =#
-            # ("main_clean.jl", false),
-        ]
+        ("main_trimmable.jl", true),
+    #= The test below should verify that we indeed can't get a trimmed binary
+    # for the "clean" implementation, but will trigger in the future if
+    # it does start working. Unfortunately, right now it hangs indefinitely
+    # so we are commenting it out. =#
+    # ("main_clean.jl", false),
+    ]
         binpath = tempname()
         cmd = `$(Base.julia_cmd()) --project=. --depwarn=error $(JULIAC) --experimental --trim=unsafe-warn --output-exe $(binpath) $(mainfile)`
 

From ca0d0f2a8cf752a68c48ab88cf4c850bb1acbc49 Mon Sep 17 00:00:00 2001
From: Romeo Valentin <romeov@stanford.edu>
Date: Tue, 5 Aug 2025 13:17:59 -0700
Subject: [PATCH 18/19] Add segfault case

[skip ci]
---
 test/trim/main_segfault.jl | 10 ++++++++++
 test/trim/runtests.jl      |  1 +
 2 files changed, 11 insertions(+)
 create mode 100644 test/trim/main_segfault.jl

diff --git a/test/trim/main_segfault.jl b/test/trim/main_segfault.jl
new file mode 100644
index 000000000..91ef5ef47
--- /dev/null
+++ b/test/trim/main_segfault.jl
@@ -0,0 +1,10 @@
+module MyModule
+include("./optimization_trimmable.jl")
+end
+
+function (@main)(argv::Vector{String})::Cint
+    λ = parse(Float64, argv[2])
+    sol = MyModule.TestModuleTrimmable.minimize(λ)
+    println(Core.stdout, sum(sol.u))
+    return 0
+end
diff --git a/test/trim/runtests.jl b/test/trim/runtests.jl
index a53aa77e0..5af443581 100644
--- a/test/trim/runtests.jl
+++ b/test/trim/runtests.jl
@@ -53,6 +53,7 @@ end
     # it does start working. Unfortunately, right now it hangs indefinitely
     # so we are commenting it out. =#
     # ("main_clean.jl", false),
+        ("main_segfault.jl", false),
     ]
         binpath = tempname()
         cmd = `$(Base.julia_cmd()) --project=. --depwarn=error $(JULIAC) --experimental --trim=unsafe-warn --output-exe $(binpath) $(mainfile)`

From 6eca9581849f825f4f8e58bb1c94c96a4b103100 Mon Sep 17 00:00:00 2001
From: Romeo Valentin <romeov@stanford.edu>
Date: Thu, 7 Aug 2025 11:10:52 -0700
Subject: [PATCH 19/19] Bump CPUSummary, use upstream Polyester

See https://github.com/SciML/NonlinearSolve.jl/pull/665#issuecomment-3165081370
---
 test/trim/Project.toml | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/test/trim/Project.toml b/test/trim/Project.toml
index 88a8ac1b3..a30f60ae2 100644
--- a/test/trim/Project.toml
+++ b/test/trim/Project.toml
@@ -3,6 +3,7 @@ uuid = "7e54ada7-ece5-4046-aa01-512d530850d8"
 
 [deps]
 ADTypes = "47edcb42-4c32-4615-8424-f2b9edc5f35b"
+CPUSummary = "2a0fbf3d-bb9c-48f3-b0a9-814d99fd7ab9"
 DiffEqBase = "2b5f629d-d688-5b77-993f-72d75c75574e"
 ForwardDiff = "f6369f11-7733-5829-9624-2563aa707210"
 JET = "c3a54625-cd67-489e-a8e7-0a5a0ff4e31b"
@@ -22,16 +23,13 @@ ForwardDiff = {url = "https://github.com/RomeoV/ForwardDiff.jl", rev="rv/remove-
 # Use of `deepcopy` is tracked at https://github.com/SciML/LinearSolve.jl/issues/648.
 LinearSolve = {url = "https://github.com/RomeoV/LinearSolve.jl", rev="rv/remove-linsolve-forwarddiff-special-path"}
 NonlinearSolveFirstOrder = {path = "../../lib/NonlinearSolveFirstOrder"}
-# Remove use of CPUSummary which segfaults trimmed binary. Tracked at https://github.com/JuliaSIMD/Polyester.jl/pull/163.
-Polyester = {url = "https://github.com/RomeoV/Polyester.jl", rev="master"}
-# Remove use of CPUSummary which segfaults trimmed binary. Tracked at https://github.com/JuliaSIMD/PolyesterWeave.jl/pull/28
-PolyesterWeave = {url = "https://github.com/RomeoV/PolyesterWeave.jl", rev="main"}
 # Fix a type instability. Tracked at https://github.com/SciML/SciMLBase.jl/pull/1074.
 SciMLBase = {url = "https://github.com/AayushSabharwal/SciMLBase.jl", rev="as/fix-jet-opt"}
 
 
 [compat]
 ADTypes = "1.15.0"
+CPUSummary = "0.2.7"
 DiffEqBase = "6.179.0"
 ForwardDiff = "1.0.1"
 LinearAlgebra = "1.12.0"