IntegroDiff tests fail with spvals/SparseArrays error during Zygote differentiation #1014
Description
Summary
The IntegroDiff tests (7 test items) fail during Zygote differentiation through Cubature/Integrals.jl with an UndefVarError: spvals not defined error. This appears to be related to SparseArrays not being properly loaded in the Zygote differentiation path through Cubature.
Error
ERROR: UndefVarError: `spvals` not defined
The error occurs during backward pass through Zygote when differentiating through integral computations that use Cubature.
Affected Tests
All 7 IntegroDiff tests in test/IDE_tests.jl:
- IntegroDiff Example 1 -- 1D
- IntegroDiff Example 2 -- 1D (integral bound not including whole spatial domain)
- IntegroDiff Example 3 -- 1D (integral term inside the chain rule)
- IntegroDiff Example 4 -- 2D (integral w.r.t. x)
- IntegroDiff Example 5 -- 2D (integral w.r.t. y)
- IntegroDiff Example 6 -- 2D (integral w.r.t. x with separate kernel function)
- IntegroDiff Example 7 -- System of 2D integro-differential equation
Current Status
Tests are temporarily skipped in PR #1013 to unblock CI.
Related
This is likely related to the same Zygote/Cubature/Integrals.jl compatibility issues affecting QuadratureTraining methods.
References
- PR Fix compatibility with ModelingToolkit 11, Symbolics 7, and SymbolicUtils 4 #1013 where tests were skipped
- Similar issues may exist in Integrals.jl or Cubature.jl repos