Multi-threaded compilation of project packages hang, works after Julia restart

Internals & Design
1

I’m running Julia 1.12

julia> versioninfo()
Julia Version 1.12.6
Commit 15346901f00 (2026-04-09 19:20 UTC)
Build Info:
  Official https://julialang.org release
Platform Info:
  OS: Linux (x86_64-linux-gnu)
  CPU: 128 × AMD Ryzen Threadripper PRO 9985WX 64-Cores
  WORD_SIZE: 64
  LLVM: libLLVM-18.1.7 (ORCJIT, znver5)
  GC: Built with stock GC
Threads: 128 default, 1 interactive, 128 GC (on 128 virtual cores)
Environment:
  JULIA_NUM_THREADS = auto

As I was debugging a rather large project, I think I ended up in an state that more or less required me to remove .julia/compiled/v1.12.

When running precompile on my project, the REPL seemed to run indefinitely while compiling OrdinaryDiffEqVerner, which was package 705/711. After 30 minutes, I decided to kill it, restart and recompile, and my remaining 6 packages compiled immediately.

I’m curious to know how this can happen? I imagine this is not necessarily related to this specific package, but are we in a situation where race conditions can arise during precompilation?