Merge pull request #1137 from ChrisRackauckas-Claude/add-enzyme-sensealg-inactive

Add Enzyme extension to make AbstractSensitivityAlgorithm inactive

Author: ChrisRackauckas

Project.toml

@@ -37,6 +37,7 @@ SymbolicIndexingInterface = "2efcf032-c050-4f8e-a9bb-153293bab1f5"
 ChainRules = "082447d4-558c-5d27-93f4-14fc19e9eca2"
 ChainRulesCore = "d360d2e6-b24c-11e9-a2a3-2a2ae2dbcce4"
 Distributions = "31c24e10-a181-5473-b8eb-7969acd0382f"
+EnzymeRules = "b2b7a20a-8ddc-4497-9a0a-d49b80ff0020"
 ForwardDiff = "f6369f11-7733-5829-9624-2563aa707210"
 MLStyle = "d8e11817-5142-5d16-987a-aa16d5891078"
 Makie = "ee78f7c6-11fb-53f2-987a-cfe4a2b5a57a"
@@ -54,6 +55,7 @@ Zygote = "e88e6eb3-aa80-5325-afca-941959d7151f"
 [extensions]
 SciMLBaseChainRulesCoreExt = "ChainRulesCore"
 SciMLBaseDistributionsExt = "Distributions"
+SciMLBaseEnzymeExt = "EnzymeRules"
 SciMLBaseForwardDiffExt = "ForwardDiff"
 SciMLBaseMLStyleExt = "MLStyle"
 SciMLBaseMakieExt = "Makie"
@@ -80,6 +82,7 @@ ConstructionBase = "1.5"
 Distributed = "1.10"
 Distributions = "0.25"
 DocStringExtensions = "0.9"
+EnzymeRules = "0.1"
 EnumX = "1"
 ForwardDiff = "0.10.36, 1"
 FunctionWrappersWrappers = "0.1.3"

ext/SciMLBaseEnzymeExt.jl

@@ -0,0 +1,18 @@
+module SciMLBaseEnzymeExt
+
+using SciMLBase
+import EnzymeRules
+
+# Enzyme rules for SciMLBase abstract types
+#
+# Sensitivity algorithms define HOW to compute derivatives, not WHAT to differentiate.
+# They should be treated as inactive (constant) during Enzyme differentiation to prevent
+# errors when they are stored in problem structures that Enzyme differentiates through.
+#
+# This fixes issues like SciMLSensitivity.jl#1225 where passing `sensealg` to ODEProblem 
+# constructor would fail with Enzyme.
+
+# All sensitivity algorithm types should be inactive for Enzyme differentiation
+EnzymeRules.inactive_type(::Type{<:AbstractSensitivityAlgorithm}) = true
+
+end