Move heavy AD backends (Enzyme/Mooncake) into a group env for FIRK and MIRK

BoundaryValueDiffEqFIRK and BoundaryValueDiffEqMIRK each list Enzyme and
Mooncake in their old-style [extras]/[targets].test but not in [weakdeps].
Under the sublibrary Downgrade lane (DowngradeSublibraries.yml runs each lib's
Core group at floor) these extra-only heavy backends are merged into [deps] as
hard deps and force a large joint at-floor resolve of the whole graph.

Move the different-AD-backend compatibility tests (the only files that use
Enzyme/Mooncake) into a dedicated AD test group with its own
test/AD/Project.toml, auto-activated by run_tests before the AD body runs
(same mechanism the existing QA group uses). The heavy backends now resolve in
the AD group env, so the main test environment (Core/EXPANDED/NESTED) no longer
carries them and the Downgrade base resolve drops them.

- FIRK: move test/expanded/ad_tests.jl -> test/AD/ad_tests.jl; add AD group +
  test_groups.toml entry; drop Enzyme/Mooncake from [extras]/[targets].test and
  their [compat] (extra-only, not weakdeps).
- MIRK: move test/Core/ad_tests.jl -> test/AD/ad_tests.jl; same wiring and
  Project.toml trim.

Downgrade base resolve verified (jdc-52 harness, Julia 1): BEFORE pulls full
Enzyme+Mooncake into the base manifest; AFTER only lightweight EnzymeCore
remains transitively. AD group env instantiates Enzyme/Mooncake/ForwardDiff by
path against the developed sublibrary.

Co-Authored-By: Chris Rackauckas <accounts@chrisrackauckas.com>

Author: ChrisRackauckas

lib/BoundaryValueDiffEqFIRK/Project.toml

@@ -37,13 +37,11 @@ BoundaryValueDiffEqCore = "2.2"
 ConcreteStructs = "0.2.3"
 DiffEqDevTools = "2.44, 3"
 DifferentiationInterface = "0.7.15"
-Enzyme = "0.13.33"
 FastAlmostBandedMatrices = "0.1.4"
 FastClosures = "0.3.2"
 ForwardDiff = "0.10.38, 1"
 LinearAlgebra = "1.10"
 LinearSolve = "2.36.2, 3"
-Mooncake = "0.4.146, 0.5"
 OrdinaryDiffEqRosenbrock = "1.15.1, 2"
 PreallocationTools = "1.2"
 PrecompileTools = "1.2"
@@ -63,9 +61,7 @@ julia = "1.10"
 [extras]
 SafeTestsets = "1bc83da4-3b8d-516f-aca4-4fe02f6d838f"
 DiffEqDevTools = "f3b72e0c-5b89-59e1-b016-84e28bfd966d"
-Enzyme = "7da242da-08ed-463a-9acd-ee780be4f1d9"
 LinearSolve = "7ed4a6bd-45f5-4d41-b270-4a48e9bafcae"
-Mooncake = "da2b9cff-9c12-43a0-ae48-6db2b0edb7d6"
 OrdinaryDiffEqRosenbrock = "43230ef6-c299-4910-a778-202eb28ce4ce"
 Random = "9a3f8284-a2c9-5f02-9a11-845980a1fd5c"
 RecursiveArrayTools = "731186ca-8d62-57ce-b412-fbd966d074cd"
@@ -74,4 +70,4 @@ StaticArrays = "90137ffa-7385-5640-81b9-e52037218182"
 Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
 
 [targets]
-test = ["DiffEqDevTools", "Enzyme", "LinearSolve", "Mooncake", "OrdinaryDiffEqRosenbrock", "Random", "RecursiveArrayTools", "SciMLTesting", "StaticArrays", "Test", "SafeTestsets"]
+test = ["DiffEqDevTools", "LinearSolve", "OrdinaryDiffEqRosenbrock", "Random", "RecursiveArrayTools", "SciMLTesting", "StaticArrays", "Test", "SafeTestsets"]

lib/BoundaryValueDiffEqFIRK/test/AD/Project.toml

@@ -0,0 +1,24 @@
+[deps]
+BoundaryValueDiffEqCore = "56b672f2-a5fe-4263-ab2d-da677488eb3a"
+BoundaryValueDiffEqFIRK = "85d9eb09-370e-4000-bb32-543851f73618"
+Enzyme = "7da242da-08ed-463a-9acd-ee780be4f1d9"
+ForwardDiff = "f6369f11-7733-5829-9624-2563aa707210"
+Mooncake = "da2b9cff-9c12-43a0-ae48-6db2b0edb7d6"
+SafeTestsets = "1bc83da4-3b8d-516f-aca4-4fe02f6d838f"
+SciMLTesting = "09d9d899-5365-40a9-917a-5f67fddea283"
+Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
+
+[sources]
+BoundaryValueDiffEqCore = {path = "../../../BoundaryValueDiffEqCore"}
+BoundaryValueDiffEqFIRK = {path = "../.."}
+
+[compat]
+BoundaryValueDiffEqCore = "2"
+BoundaryValueDiffEqFIRK = "1"
+Enzyme = "0.13.33"
+ForwardDiff = "0.10.38, 1"
+Mooncake = "0.4.146, 0.5"
+SafeTestsets = "0.1.0"
+SciMLTesting = "1.7"
+Test = "1.10"
+julia = "1.10"

…alueDiffEqFIRK/test/expanded/ad_tests.jl …ndaryValueDiffEqFIRK/test/AD/ad_tests.jllib/BoundaryValueDiffEqFIRK/test/expanded/ad_tests.jl renamed to lib/BoundaryValueDiffEqFIRK/test/AD/ad_tests.jl lib/BoundaryValueDiffEqFIRK/test/expanded/ad_tests.jl renamed to lib/BoundaryValueDiffEqFIRK/test/AD/ad_tests.jl

@@ -15,7 +15,6 @@ run_tests(;
         "EXPANDED" => function ()
             @time @safetestset "FIRK Expanded Basic Tests" include("expanded/firk_basic_tests.jl")
             @time @safetestset "FIRK Expanded NLLS Tests" include("expanded/nlls_tests.jl")
-            @time @safetestset "FIRK Expanded AD Tests" include("expanded/ad_tests.jl")
             @time @safetestset "FIRK Expanded Ensemble Tests" include("expanded/ensemble_tests.jl")
             @time @safetestset "FIRK Expanded Singular BVP Tests" include("expanded/singular_bvp_tests.jl")
             return @time @safetestset "FIRK Expanded VectorOfVector Initials Tests" include("expanded/vectorofvector_initials_tests.jl")
@@ -26,6 +25,16 @@ run_tests(;
             @time @safetestset "FIRK Nested Ensemble Tests" include("nested/ensemble_tests.jl")
             return @time @safetestset "FIRK Nested VectorOfVector Initials Tests" include("nested/vectorofvector_initials_tests.jl")
         end,
+        # AD: the different-AD-backend compatibility tests. Enzyme and Mooncake are
+        # heavy optional backends kept out of the main test environment (they force a
+        # large joint at-floor resolve on the Downgrade lane); they live in this
+        # group's own test/AD/Project.toml, auto-activated before the body runs.
+        "AD" => (;
+            env = joinpath(@__DIR__, "AD"),
+            body = function ()
+                return @time @safetestset "FIRK Expanded AD Tests" include("AD/ad_tests.jl")
+            end,
+        ),
     ),
     qa = (;
         env = joinpath(@__DIR__, "qa"),
@@ -35,7 +44,7 @@ run_tests(;
             return @time @safetestset "Quality Assurance" include("qa/qa.jl")
         end,
     ),
-    # "All" runs EXPANDED + NESTED + QA. "Core" is intentionally excluded: its basic
-    # tests are already covered inside EXPANDED and NESTED.
-    all = ["EXPANDED", "NESTED", "QA"],
+    # "All" runs EXPANDED + NESTED + AD + QA. "Core" is intentionally excluded: its
+    # basic tests are already covered inside EXPANDED and NESTED.
+    all = ["EXPANDED", "NESTED", "AD", "QA"],
 )

lib/BoundaryValueDiffEqFIRK/test/runtests.jl

@@ -18,5 +18,13 @@ timeout = 240
 versions = ["lts", "1", "pre"]
 timeout = 240
 
+# AD: different-AD-backend (Enzyme/Mooncake) compatibility tests. The heavy
+# optional backends live in test/AD/Project.toml (kept out of the main test env so
+# the Downgrade lane does not force a joint at-floor resolve of them). Matches the
+# EXPANDED/NESTED version matrix.
+[AD]
+versions = ["lts", "1", "pre"]
+timeout = 240
+
 [QA]
 versions = ["lts", "1"]

lib/BoundaryValueDiffEqFIRK/test/test_groups.toml

@@ -35,13 +35,11 @@ BoundaryValueDiffEqCore = "2.2"
 ConcreteStructs = "0.2.3"
 DiffEqDevTools = "2.44, 3"
 DifferentiationInterface = "0.7.15"
-Enzyme = "0.13.33"
 FastAlmostBandedMatrices = "0.1.4"
 FastClosures = "0.3.2"
 ForwardDiff = "0.10.38, 1"
 LinearAlgebra = "1.10"
 LinearSolve = "2.36.2, 3"
-Mooncake = "0.4, 0.5"
 OptimizationIpopt = "1"
 OrdinaryDiffEqRosenbrock = "1, 2"
 PreallocationTools = "1.2"
@@ -62,9 +60,7 @@ julia = "1.10"
 
 [extras]
 DiffEqDevTools = "f3b72e0c-5b89-59e1-b016-84e28bfd966d"
-Enzyme = "7da242da-08ed-463a-9acd-ee780be4f1d9"
 LinearSolve = "7ed4a6bd-45f5-4d41-b270-4a48e9bafcae"
-Mooncake = "da2b9cff-9c12-43a0-ae48-6db2b0edb7d6"
 OptimizationIpopt = "43fad042-7963-4b32-ab19-e2a4f9a67124"
 OrdinaryDiffEqRosenbrock = "43230ef6-c299-4910-a778-202eb28ce4ce"
 Random = "9a3f8284-a2c9-5f02-9a11-845980a1fd5c"
@@ -75,4 +71,4 @@ StaticArrays = "90137ffa-7385-5640-81b9-e52037218182"
 Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
 
 [targets]
-test = ["DiffEqDevTools", "Enzyme", "LinearSolve", "Mooncake", "OptimizationIpopt", "OrdinaryDiffEqRosenbrock", "Random", "RecursiveArrayTools", "SafeTestsets", "SciMLTesting", "StaticArrays", "Test"]
+test = ["DiffEqDevTools", "LinearSolve", "OptimizationIpopt", "OrdinaryDiffEqRosenbrock", "Random", "RecursiveArrayTools", "SafeTestsets", "SciMLTesting", "StaticArrays", "Test"]

lib/BoundaryValueDiffEqMIRK/Project.toml

@@ -0,0 +1,24 @@
+[deps]
+BoundaryValueDiffEqCore = "56b672f2-a5fe-4263-ab2d-da677488eb3a"
+BoundaryValueDiffEqMIRK = "1a22d4ce-7765-49ea-b6f2-13c8438986a6"
+Enzyme = "7da242da-08ed-463a-9acd-ee780be4f1d9"
+ForwardDiff = "f6369f11-7733-5829-9624-2563aa707210"
+Mooncake = "da2b9cff-9c12-43a0-ae48-6db2b0edb7d6"
+SafeTestsets = "1bc83da4-3b8d-516f-aca4-4fe02f6d838f"
+SciMLTesting = "09d9d899-5365-40a9-917a-5f67fddea283"
+Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
+
+[sources]
+BoundaryValueDiffEqCore = {path = "../../../BoundaryValueDiffEqCore"}
+BoundaryValueDiffEqMIRK = {path = "../.."}
+
+[compat]
+BoundaryValueDiffEqCore = "2"
+BoundaryValueDiffEqMIRK = "1"
+Enzyme = "0.13.33"
+ForwardDiff = "0.10.38, 1"
+Mooncake = "0.4, 0.5"
+SafeTestsets = "0.1.0"
+SciMLTesting = "1.7"
+Test = "1.10"
+julia = "1.10"

lib/BoundaryValueDiffEqMIRK/test/AD/Project.toml

@@ -7,11 +7,22 @@ run_tests(;
         @time @safetestset "MIRK Basic Tests" include("Core/mirk_basic_tests.jl")
         @time @safetestset "MIRK NLLS Tests" include("Core/nlls_tests.jl")
         @time @safetestset "MIRK Ensemble Tests" include("Core/ensemble_tests.jl")
-        @time @safetestset "MIRK AD Tests" include("Core/ad_tests.jl")
         @time @safetestset "MIRK Singular BVP Tests" include("Core/singular_bvp_tests.jl")
         @time @safetestset "MIRK VectorOfVector Initials Tests" include("Core/vectorofvector_initials_tests.jl")
         return @time @safetestset "MIRK Dynamic Optimization Tests" include("Core/dynamic_optimization_tests.jl")
     end,
+    groups = Dict(
+        # AD: the different-AD-backend compatibility tests. Enzyme and Mooncake are
+        # heavy optional backends kept out of the main test environment (they force a
+        # large joint at-floor resolve on the Downgrade lane); they live in this
+        # group's own test/AD/Project.toml, auto-activated before the body runs.
+        "AD" => (;
+            env = joinpath(@__DIR__, "AD"),
+            body = function ()
+                return @time @safetestset "MIRK AD Tests" include("AD/ad_tests.jl")
+            end,
+        ),
+    ),
     qa = (;
         env = joinpath(@__DIR__, "qa"),
         body = function ()
@@ -20,5 +31,5 @@ run_tests(;
             return @time @safetestset "Quality Assurance" include("qa/qa.jl")
         end,
     ),
-    all = ["Core", "QA"],
+    all = ["Core", "AD", "QA"],
 )

…aryValueDiffEqMIRK/test/Core/ad_tests.jl …ndaryValueDiffEqMIRK/test/AD/ad_tests.jllib/BoundaryValueDiffEqMIRK/test/Core/ad_tests.jl renamed to lib/BoundaryValueDiffEqMIRK/test/AD/ad_tests.jl lib/BoundaryValueDiffEqMIRK/test/Core/ad_tests.jl renamed to lib/BoundaryValueDiffEqMIRK/test/AD/ad_tests.jl

@@ -9,5 +9,11 @@
 [Core]
 versions = ["lts", "1", "pre"]
 
+# AD: different-AD-backend (Enzyme/Mooncake) compatibility tests. The heavy
+# optional backends live in test/AD/Project.toml (kept out of the main test env so
+# the Downgrade lane does not force a joint at-floor resolve of them).
+[AD]
+versions = ["lts", "1", "pre"]
+
 [QA]
 versions = ["lts", "1"]