Flux Enzyme tests are failing

[CarloLucibello]

Not sure why but it can be seen in FluxML/Flux.jl#2464
e.g.
https://github.com/FluxML/Flux.jl/actions/runs/10435007814/job/28898510960?pr=2464#step:6:530

[wsmoses]

@vchuravy @maleadt any idea what this is? Looks like GPUCompiler.jl fails to emit code?

You may need to write `f(x::Vararg{T})` rather than `f(x::Vararg{<:T})` or `f(x::Vararg{T}) where T` instead of `f(x::Vararg{T} where T)`.
: Error During Test at D:\a\Flux.jl\Flux.jl\test\ext_enzyme\enzyme.jl:121
  Got exception outside of a @test
  AssertionError: Static compilation failed
  Stacktrace:
    [1] compile_method_instance(job::GPUCompiler.CompilerJob)
      @ GPUCompiler C:\Users\runneradmin\.julia\packages\GPUCompiler\Y4hSX\src\jlgen.jl:739
    [2] macro expansion
      @ C:\Users\runneradmin\.julia\packages\TimerOutputs\Lw5SP\src\TimerOutput.jl:253 [inlined]
    [3] irgen(job::GPUCompiler.CompilerJob)
      @ GPUCompiler C:\Users\runneradmin\.julia\packages\GPUCompiler\Y4hSX\src\irgen.jl:4
    [4] macro expansion
      @ C:\Users\runneradmin\.julia\packages\GPUCompiler\Y4hSX\src\driver.jl:208 [inlined]
    [5] macro expansion
      @ C:\Users\runneradmin\.julia\packages\TimerOutputs\Lw5SP\src\TimerOutput.jl:253 [inlined]
    [6] macro expansion
      @ C:\Users\runneradmin\.julia\packages\GPUCompiler\Y4hSX\src\driver.jl:207 [inlined]
    [7] emit_llvm(job::GPUCompiler.CompilerJob; libraries::Bool, toplevel::Bool, optimize::Bool, cleanup::Bool, only_entry::Bool, validate::Bool)
      @ GPUCompiler C:\Users\runneradmin\.julia\packages\GPUCompiler\Y4hSX\src\utils.jl:103
    [8] emit_llvm
      @ C:\Users\runneradmin\.julia\packages\GPUCompiler\Y4hSX\src\utils.jl:97 [inlined]
    [9] codegen(output::Symbol, job::GPUCompiler.CompilerJob; libraries::Bool, toplevel::Bool, optimize::Bool, cleanup::Bool, strip::Bool, validate::Bool, only_entry::Bool, parent_job::Nothing)
      @ GPUCompiler C:\Users\runneradmin\.julia\packages\GPUCompiler\Y4hSX\src\driver.jl:136
   [10] codegen
      @ C:\Users\runneradmin\.julia\packages\GPUCompiler\Y4hSX\src\driver.jl:115 [inlined]
   [11] codegen(output::Symbol, job::GPUCompiler.CompilerJob{Enzyme.Compiler.EnzymeTarget, Enzyme.Compiler.EnzymeCompilerParams}; libraries::Bool, deferred_codegen::Bool, optimize::Bool, toplevel::Bool, strip::Bool, validate::Bool, only_entry::Bool, parent_job::Nothing)
      @ Enzyme.Compiler C:\Users\runneradmin\.julia\packages\Enzyme\OOd6p\src\compiler.jl:5525
   [12] codegen
      @ C:\Users\runneradmin\.julia\packages\Enzyme\OOd6p\src\compiler.jl:[549](https://github.com/FluxML/Flux.jl/actions/runs/10435007814/job/28898510960?pr=2464#step:6:552)3 [inlined]
   [13] _thunk(job::GPUCompiler.CompilerJob{Enzyme.Compiler.EnzymeTarget, Enzyme.Compiler.EnzymeCompilerParams}, postopt::Bool)
      @ Enzyme.Compiler C:\Users\runneradmin\.julia\packages\Enzyme\OOd6p\src\compiler.jl:7103
   [14] _thunk
      @ C:\Users\runneradmin\.julia\packages\Enzyme\OOd6p\src\compiler.jl:7103 [inlined]
   [15] cached_compilation
      @ C:\Users\runneradmin\.julia\packages\Enzyme\OOd6p\src\compiler.jl:7144 [inlined]
   [16] thunkbase(ctx::LLVM.Context, mi::Core.MethodInstance, ::Val{0x0000000000007d27}, ::Type{EnzymeCore.Const{var"#loss#455"}}, ::Type{Active}, tt::Type{Tuple{Duplicated{Chain{Tuple{Dense{typeof(relu), Matrix{Float32}, Vector{Float32}}, Dense{typeof(identity), Matrix{Float32}, Vector{Float32}}}}}, Duplicated{Vector{Float32}}}}, ::Val{Enzyme.API.DEM_ReverseModeCombined}, ::Val{1}, ::Val{(false, false, false)}, ::Val{true}, ::Val{false}, ::Type{EnzymeCore.FFIABI}, ::Val{true})
      @ Enzyme.Compiler C:\Users\runneradmin\.julia\packages\Enzyme\OOd6p\src\compiler.jl:7217
   [17] #s2048#18999
      @ C:\Users\runneradmin\.julia\packages\Enzyme\OOd6p\src\compiler.jl:7269 [inlined]
   [18] var"#s2048#18999"(FA::Any, A::Any, TT::Any, Mode::Any, ModifiedBetween::Any, width::Any, ReturnPrimal::Any, ShadowInit::Any, World::Any, ABI::Any, ErrIfFuncWritten::Any, ::Any, ::Type, ::Type, ::Type, tt::Any, ::Type, ::Type, ::Type, ::Type, ::Type, ::Type, ::Any)
      @ Enzyme.Compiler .\none:0
   [19] (::Core.GeneratedFunctionStub)(::UInt64, ::LineNumberNode, ::Any, ::Vararg{Any})
      @ Core .\boot.jl:602
   [20] autodiff
      @ C:\Users\runneradmin\.julia\packages\Enzyme\OOd6p\src\Enzyme.jl:315 [inlined]
   [21] autodiff(::EnzymeCore.ReverseMode{true, EnzymeCore.FFIABI, false, false}, ::var"#loss#455", ::Type{Active}, ::Duplicated{Chain{Tuple{Dense{typeof(relu), Matrix{Float32}, Vector{Float32}}, Dense{typeof(identity), Matrix{Float32}, Vector{Float32}}}}}, ::Duplicated{Vector{Float32}})
      @ Enzyme C:\Users\runneradmin\.julia\packages\Enzyme\OOd6p\src\Enzyme.jl:332
   [22] gradient_ez(::Function, ::Chain{Tuple{Dense{typeof(relu), Matrix{Float32}, Vector{Float32}}, Dense{typeof(identity), Matrix{Float32}, Vector{Float32}}}}, ::Vararg{Any})
      @ Main D:\a\Flux.jl\Flux.jl\test\ext_enzyme\enzyme.jl:30
   [23] test_enzyme_grad(loss::var"#loss#455", model::Chain{Tuple{Dense{typeof(relu), Matrix{Float32}, Vector{Float32}}, Dense{typeof(identity), Matrix{Float32}, Vector{Float32}}}}, x::Vector{Float32})
      @ Main D:\a\Flux.jl\Flux.jl\test\ext_enzyme\enzyme.jl:53
   [24] macro expansion
      @ D:\a\Flux.jl\Flux.jl\test\ext_enzyme\enzyme.jl:123 [inlined]
   [25] macro expansion
      @ C:\hostedtoolcache\windows\julia\1.10.4\x64\share\julia\stdlib\v1.10\Test\src\Test.jl:1577 [inlined]
   [26] macro expansion
      @ D:\a\Flux.jl\Flux.jl\test\ext_enzyme\enzyme.jl:122 [inlined]
   [27] macro expansion
      @ C:\hostedtoolcache\windows\julia\1.10.4\x64\share\julia\stdlib\v1.10\Test\src\Test.jl:1577 [inlined]
   [28] top-level scope
      @ D:\a\Flux.jl\Flux.jl\test\ext_enzyme\enzyme.jl:96
   [29] include(fname::String)
      @ Base.MainInclude .\client.jl:489
   [30] macro expansion
      @ D:\a\Flux.jl\Flux.jl\test\runtests.jl:146 [inlined]
   [31] macro expansion
      @ C:\hostedtoolcache\windows\julia\1.10.4\x64\share\julia\stdlib\v1.10\Test\src\Test.jl:1577 [inlined]
   [32] macro expansion
      @ D:\a\Flux.jl\Flux.jl\test\runtests.jl:144 [inlined]
   [33] macro expansion
      @ C:\hostedtoolcache\windows\julia\1.10.4\x64\share\julia\stdlib\v1.10\Test\src\Test.jl:1577 [inlined]
   [34] top-level scope
      @ D:\a\Flux.jl\Flux.jl\test\runtests.jl:22
   [35] include(fname::String)
      @ Base.MainInclude .\client.jl:489
   [36] top-level scope
      @ none:6
   [37] eval
      @ .\boot.jl:385 [inlined]
   [38] exec_options(opts::Base.JLOptions)
      @ Base .\client.jl:291
   [39] _start()
      @ Base .\client.jl:[552](https://github.com/FluxML/Flux.jl/actions/runs/10435007814/job/28898510960?pr=2464#step:6:555)
testing f64(Chain(Dense, Dense))

[wsmoses]

cc @gbaraldi if you have any idea what's up

[wsmoses]

@CarloLucibello is this still the case, I don't see failures on Flux CI?

Reopen if so