Segfault in libcurl when Download.download is used by GAP.jl

[fingolfin]

Just got this in CI (with Julia nightly on Ubuntu):

...
   Installed GAP ─────────────────── v0.7.1

signal (11): Segmentation fault
in expression starting at none:1
curl_multi_socket_action at /opt/hostedtoolcache/julia/nightly/x64/bin/../lib/julia/libcurl.so (unknown line)
unknown function (ip: 0x7faf1c7ff85f)
lock at ./lock.jl:190
do_multi at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.8/Downloads/src/Curl/Multi.jl:101 [inlined]
#33 at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.8/Downloads/src/Curl/Multi.jl:118 [inlined]
macro expansion at ./asyncevent.jl:256 [inlined]
#644 at ./task.jl:123
jfptr_YY.644_28316.clone_1 at /opt/hostedtoolcache/julia/nightly/x64/lib/julia/sys.so (unknown line)
_jl_invoke at /buildworker/worker/package_linux64/build/src/gf.c:2256 [inlined]
ijl_apply_generic at /buildworker/worker/package_linux64/build/src/gf.c:2438
jl_apply at /buildworker/worker/package_linux64/build/src/julia.h:1773 [inlined]
start_task at /buildworker/worker/package_linux64/build/src/task.c:924
Allocations: 6158086 (Pool: 6151205; Big: 6881); GC: 11
/home/runner/work/_temp/6a144cae-5e54-4c6b-9469-8be3553df47b.sh: line 1:  1646 Segmentation fault      (core dumped) julia --color=yes --project=@. -e 'using Pkg; if VERSION >= v"1.1.0-rc1"; Pkg.build(verbose=true); else Pkg.build(); end'
Error: Process completed with exit code 139.
Run tests

This is probably to be classified as a bug in the Downloads stdlib, perhaps GC related, but I don't have time to dig deeper right now. We can file it if we figure out more...

[benlorenz]

This seems to be known and is dicussed here: JuliaLang/Pkg.jl#2802

[thofma]

Fixed upstream.