1.10: Apparent segfault in precompilation serialization

[wsmoses]

I'm not sure how to properly debug this.

But essentially here (EnzymeAD/Reactant.jl#353 (comment)) we're trying to add precompilation to reactant. Everything is fine on 1.11. On 1.10, loading of the serializatized object hits a julia assertion error in particular here:

julia/src/method.c

Line 1248 in 4976d05

assert(key == 0);

This data isn't written to after mmaping in the compiled code, and where it asserts so I presume it's a bug in Julia's precompilation.

cc @gbaraldi @vchuravy @vtjnash @mofeing

[vchuravy]

What is a MWE for this? The referenced branch got merged and it is unclear what should be run to reproduce the issue.

[mofeing]

I think you just need to comment this if so you run the branch on 1.10 https://github.com/EnzymeAD/Reactant.jl/blob/75c31406631d3a31502fafee39bd36d734684865/src/Precompile.jl#L42-L43

[vchuravy]

No joy.

julia> using Reactant
2025-01-06 13:50:09.817878: E external/xla/xla/stream_executor/cuda/cuda_platform.cc:51] failed call to cuInit: INTERNAL: CUDA error: Failed call to cuInit: CUDA_ERROR_NO_DEVICE: no CUDA-capable device is detected
AssertionError("No visible GPU devices.")

on 1.10-debug with that branch commented out.

[vchuravy]

Pure speculation, but it might be #54738

[wsmoses]

EnzymeAD/Reactant.jl#484