Fix type inference regression with PIController on Julia 1.10 LTS#3033
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ChrisRackauckas-Claude wants to merge 1 commit intoSciML:masterfrom
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Fix type inference regression with PIController on Julia 1.10 LTS#3033ChrisRackauckas-Claude wants to merge 1 commit intoSciML:masterfrom
ChrisRackauckas-Claude wants to merge 1 commit intoSciML:masterfrom
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…ia 1.10 LTS
The `@inferred init()` tests were failing on Julia 1.10 LTS because the
return type was inferred as Union{..PIController.., ..PIControllerCache..}
instead of a concrete type.
Root cause: Two code paths for creating controllers existed:
1. `default_controller_v7` returning new-style controllers
2. `legacy_default_controller` returning legacy controllers
Julia 1.10's type inference couldn't determine at compile time which
path would be taken, resulting in a Union type.
Changes:
- Always use `default_controller_v7` for the controller default parameter
- Enable `CompositeController` for composite algorithms instead of returning
`nothing` (which triggered the legacy fallback)
- Add `new_controller_from_legacy_params` to create new-style controllers
when legacy parameters are provided, ensuring type stability
- Replace `legacy_default_controller` call with new controller constructors
This fixes the Regression_II (LTS) test failure without breaking backwards
compatibility for users who specify legacy controller parameters.
Co-Authored-By: Chris Rackauckas <[email protected]>
Co-Authored-By: Claude Opus 4.5 <[email protected]>
ChrisRackauckas
approved these changes
Feb 3, 2026
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Summary
@inferred init()tests on Julia 1.10 LTSUnion{..PIController.., ..PIControllerCache..}instead of a concrete typeRoot Cause
Two code paths existed for creating controllers:
default_controller_v7returning new-style controllers (NewPIController→PIControllerCache)legacy_default_controllerreturning legacy controllers (PIController)Julia 1.10's type inference couldn't determine at compile time which path would be taken, resulting in a Union type.
Changes
lib/OrdinaryDiffEqCore/src/solve.jl:
default_controller_v7for the controller default parameterlegacy_default_controllercall withnew_controller_from_legacy_paramslib/OrdinaryDiffEqCore/src/alg_utils.jl:
CompositeControllerfor composite algorithms (instead of returningnothing)_default_controller_v7_tuplegenerated function for type-stable tuple creationnew_controller_from_legacy_paramsto create new-style controllers from legacy parametersTest plan
@inferred init(prob, BS3())passes on Julia 1.10.10@inferred init(prob, Tsit5())passes on Julia 1.10.10@inferred init(prob, RK4())passes on Julia 1.10.10@inferred init(prob, Vern6())passes on Julia 1.10.10solve()still works correctly for all above solvers🤖 Generated with Claude Code