PackageCompiler hangs while compiling nonincremental system image on Julia v1.11

[paulmelis]

@kristoffer.carlsson

Is this really true? I can imagine 1.11 being slower in itself, but I don’t think anything in the PackageCompiler process should use threads (except a part of the very last step in outputting the sysimage and I am not sure that even uses the number of julia threads). If you turn off threading, does 1.10 also become 40% slower?

Could you explain what part of PackageCompiler you think gets faster with your threads environment variable?

PackageCompiler gets stuck with multiple threads for some cases (e.g. `create_app` never finishes on Julia v1.11.1 when `JULIA_NUM_THREADS` is set · Issue #990 · JuliaLang/PackageCompiler.jl · GitHub and PackageCompiler never ends on julia 1.11.0 with --threads=6 · Issue #963 · JuliaLang/PackageCompiler.jl · GitHub), so using a single thread becomes the workaround for those. Don’t know about the performance impact in general, though.