Enzyme compilation failed for HVP with broadcast

[gdalle]

Here's the MWE (tested on Enzyme v0.13.19):

import Enzyme

mydiff(x) = x[2:end] .- x[1:end-1];
sumdiff(x) = sum(mydiff(x));

Enzyme.hvp(sumdiff, float.(1:5), float.(1:5))

Here's the shortened error:

julia> Enzyme.hvp(sumdiff, float.(1:5), float.(1:5))
ERROR: Enzyme compilation failed.
Current scope: 
; Function Attrs: mustprogress willreturn

...

Stacktrace:
  [1] copy
    @ ./array.jl:350
  [2] unaliascopy
    @ ./abstractarray.jl:1516
  [3] unalias
    @ ./abstractarray.jl:1500
  [4] broadcast_unalias
    @ ./broadcast.jl:941
  [5] preprocess
    @ ./broadcast.jl:948
  [6] preprocess_args
    @ ./broadcast.jl:950
  [7] preprocess
    @ ./broadcast.jl:947
  [8] override_bc_copyto!
    @ ~/.julia/packages/Enzyme/ottqJ/src/compiler/interpreter.jl:663
  [9] copyto!
    @ ./broadcast.jl:920
 [10] override_bc_materialize
    @ ~/.julia/packages/Enzyme/ottqJ/src/compiler/interpreter.jl:719
 [11] mydiff
    @ ~/Work/GitHub/Julia/DifferentiationInterface.jl/DifferentiationInterface/test/playground.jl:3

Stacktrace:
  [1] julia_error(msg::String, val::Ptr{…}, errtype::Enzyme.API.ErrorType, data::Ptr{…}, data2::Ptr{…}, B::Ptr{…})
    @ Enzyme.Compiler ~/.julia/packages/Enzyme/ottqJ/src/errors.jl:350
  [2] julia_error(cstr::Cstring, val::Ptr{…}, errtype::Enzyme.API.ErrorType, data::Ptr{…}, data2::Ptr{…}, B::Ptr{…})
    @ Enzyme.Compiler ~/.julia/packages/Enzyme/ottqJ/src/errors.jl:176
  [3] EnzymeCreatePrimalAndGradient(logic::Enzyme.Logic, todiff::LLVM.Function, retType::Enzyme.API.CDIFFE_TYPE, constant_args::Vector{…}, TA::Enzyme.TypeAnalysis, returnValue::Bool, dretUsed::Bool, mode::Enzyme.API.CDerivativeMode, runtimeActivity::Bool, width::Int64, additionalArg::Ptr{…}, forceAnonymousTape::Bool, typeInfo::Enzyme.FnTypeInfo, uncacheable_args::Vector{…}, augmented::Ptr{…}, atomicAdd::Bool)
    @ Enzyme.API ~/.julia/packages/Enzyme/ottqJ/src/api.jl:268
  [4] enzyme!(job::GPUCompiler.CompilerJob{…}, mod::LLVM.Module, primalf::LLVM.Function, TT::Type, mode::Enzyme.API.CDerivativeMode, width::Int64, parallel::Bool, actualRetType::Type, wrap::Bool, modifiedBetween::NTuple{…} where N, returnPrimal::Bool, expectedTapeType::Type, loweredArgs::Set{…}, boxedArgs::Set{…})
    @ Enzyme.Compiler ~/.julia/packages/Enzyme/ottqJ/src/compiler.jl:1571
  [5] codegen(output::Symbol, job::GPUCompiler.CompilerJob{…}; libraries::Bool, deferred_codegen::Bool, optimize::Bool, toplevel::Bool, strip::Bool, validate::Bool, only_entry::Bool, parent_job::GPUCompiler.CompilerJob{…})
    @ Enzyme.Compiler ~/.julia/packages/Enzyme/ottqJ/src/compiler.jl:4417
  [6] codegen
    @ ~/.julia/packages/Enzyme/ottqJ/src/compiler.jl:3218 [inlined]
  [7] (::GPUCompiler.var"#187#198"{GPUCompiler.CompilerJob{…}, GPUCompiler.CompilerJob{…}})()
    @ GPUCompiler ~/.julia/packages/GPUCompiler/2CW9L/src/driver.jl:224
  [8] get!(default::GPUCompiler.var"#187#198"{…}, h::Dict{…}, key::GPUCompiler.CompilerJob{…})
    @ Base ./dict.jl:458
  [9] macro expansion
    @ ~/.julia/packages/GPUCompiler/2CW9L/src/driver.jl:223 [inlined]
 [10] 
    @ GPUCompiler ~/.julia/packages/GPUCompiler/2CW9L/src/utils.jl:108
 [11] emit_llvm
    @ ~/.julia/packages/GPUCompiler/2CW9L/src/utils.jl:106 [inlined]
 [12] codegen(output::Symbol, job::GPUCompiler.CompilerJob{…}; libraries::Bool, deferred_codegen::Bool, optimize::Bool, toplevel::Bool, strip::Bool, validate::Bool, only_entry::Bool, parent_job::Nothing)
    @ Enzyme.Compiler ~/.julia/packages/Enzyme/ottqJ/src/compiler.jl:3274
 [13] codegen
    @ ~/.julia/packages/Enzyme/ottqJ/src/compiler.jl:3218 [inlined]
 [14] _thunk(job::GPUCompiler.CompilerJob{Enzyme.Compiler.EnzymeTarget, Enzyme.Compiler.EnzymeCompilerParams}, postopt::Bool)
    @ Enzyme.Compiler ~/.julia/packages/Enzyme/ottqJ/src/compiler.jl:5265
 [15] cached_compilation(job::GPUCompiler.CompilerJob)
    @ Enzyme.Compiler ~/.julia/packages/Enzyme/ottqJ/src/compiler.jl:5306
 [16] thunkbase(mi::Core.MethodInstance, World::UInt64, FA::Type{…}, A::Type{…}, TT::Type, Mode::Enzyme.API.CDerivativeMode, width::Int64, ModifiedBetween::NTuple{…} where N, ReturnPrimal::Bool, ShadowInit::Bool, ABI::Type, ErrIfFuncWritten::Bool, RuntimeActivity::Bool)
    @ Enzyme.Compiler ~/.julia/packages/Enzyme/ottqJ/src/compiler.jl:5410
 [17] thunk_generator(world::UInt64, source::LineNumberNode, FA::Type, A::Type, TT::Type, Mode::Enzyme.API.CDerivativeMode, Width::Int64, ModifiedBetween::NTuple{…} where N, ReturnPrimal::Bool, ShadowInit::Bool, ABI::Type, ErrIfFuncWritten::Bool, RuntimeActivity::Bool, self::Any, fakeworld::Any, fa::Type, a::Type, tt::Type, mode::Type, width::Type, modifiedbetween::Type, returnprimal::Type, shadowinit::Type, abi::Type, erriffuncwritten::Type, runtimeactivity::Type)
    @ Enzyme.Compiler ~/.julia/packages/Enzyme/ottqJ/src/compiler.jl:5562
 [18] autodiff
    @ ~/.julia/packages/Enzyme/ottqJ/src/Enzyme.jl:640 [inlined]
 [19] autodiff
    @ ~/.julia/packages/Enzyme/ottqJ/src/Enzyme.jl:544 [inlined]
 [20] autodiff
    @ ~/.julia/packages/Enzyme/ottqJ/src/Enzyme.jl:516 [inlined]
 [21] hvp!
    @ ~/.julia/packages/Enzyme/ottqJ/src/sugar.jl:1105 [inlined]
 [22] hvp(f::typeof(sumdiff), x::Vector{Float64}, v::Vector{Float64})
    @ Enzyme ~/.julia/packages/Enzyme/ottqJ/src/sugar.jl:1072
 [23] top-level scope
    @ ~/Work/GitHub/Julia/DifferentiationInterface.jl/DifferentiationInterface/test/playground.jl:6
Some type information was truncated. Use `show(err)` to see complete types.

And here's the complete log:

log.txt

[wsmoses]

hm same "does this err on the latest version of enzyme" question. On main it runs for me

julia> import Enzyme

julia> mydiff(x) = x[2:end] .- x[1:end-1];

julia> sumdiff(x) = sum(mydiff(x));

julia> Enzyme.hvp(sumdiff, float.(1:5), float.(1:5))
5-element Vector{Float64}:
 0.0
 0.0
 0.0
 0.0
 0.0

[gdalle]

If I'm not mistaken, Enzyme v0.13.19 is the latest version, and currently coincides with main?