Precompile bug

[timholy]

Today FileIO and Revise stopped building due to some changes in the behavior of precompile directives. For Revise, I thought I had commented the problematic lines in timholy/Revise.jl#612, thinking that it didn't happen on Linux (and indeed the Ubuntu workers for GitHub Actions passed), but then a user reported that it happens even on Fedora: timholy/Revise.jl#613. Moreover, others have seen this in other repos, e.g., FileIO: tlnagy/TiffImages.jl#35 (comment)

Since I'm on Ubuntu I can't replicate this easily but a guess at a MWE might be something like this:

julia> foo(x; kwargs...) = x
foo (generic function with 1 method)

julia> m = @which foo(1)
foo(x; kwargs...) in Main at REPL[2]:1

julia> fbody = Base.bodyfunction(m)
#foo#5 (generic function with 1 method)

julia> methods(fbody)
# 1 method for generic function "#foo#5":
[1] var"#foo#5"(kwargs, ::typeof(foo), x) in Main at REPL[2]:1

julia> using MethodAnalysis

julia> foo(1)
1

julia> methodinstances(fbody)
1-element Vector{Core.MethodInstance}:
 MethodInstance for var"#foo#5"(::Base.Iterators.Pairs{Union{}, Union{}, Tuple{}, NamedTuple{(), Tuple{}}}, ::typeof(foo), ::Int64)

julia> precompile(fbody, (Base.Iterators.Pairs{Union{}, Union{}, Tuple{}, NamedTuple{(), Tuple{}}}, typeof(foo), Int64) )
true

I'm guessing that returns false for some people.

EDIT: actually this has nothing to do with the platform, other than the fact that the nightlies came out at different times.

[simeonschaub]

Ref c0f9666#commitcomment-47798892

[vtjnash]

Closed by #39905