Uncaught error in testsuite in CI?

[giordano]

https://github.com/JuliaTesting/ParallelTestRunner.jl/actions/runs/18476955753/job/52643555008#step:5:124

Unhandled Task ERROR: EOFError: read end of file
Stacktrace:
 [1] (::Base.var"#wait_locked#739")(s::Sockets.TCPSocket, buf::IOBuffer, nb::Int64)
   @ Base ./stream.jl:947
 [2] unsafe_read(s::Sockets.TCPSocket, p::Ptr{UInt8}, nb::UInt64)
   @ Base ./stream.jl:955
 [3] unsafe_read
   @ ./io.jl:774 [inlined]
 [4] unsafe_read(s::Sockets.TCPSocket, p::Base.RefValue{NTuple{4, Int64}}, n::Int64)
   @ Base ./io.jl:773
 [5] read!
   @ ./io.jl:775 [inlined]
 [6] deserialize_hdr_raw
   @ /opt/hostedtoolcache/julia/1.10.0/x64/share/julia/stdlib/v1.10/Distributed/src/messages.jl:167 [inlined]
 [7] message_handler_loop(r_stream::Sockets.TCPSocket, w_stream::Sockets.TCPSocket, incoming::Bool)
   @ Distributed /opt/hostedtoolcache/julia/1.10.0/x64/share/julia/stdlib/v1.10/Distributed/src/process_messages.jl:172
 [8] process_tcp_streams(r_stream::Sockets.TCPSocket, w_stream::Sockets.TCPSocket, incoming::Bool)
   @ Distributed /opt/hostedtoolcache/julia/1.10.0/x64/share/julia/stdlib/v1.10/Distributed/src/process_messages.jl:133
 [9] (::Distributed.var"#103#104"{Sockets.TCPSocket, Sockets.TCPSocket, Bool})()
   @ Distributed /opt/hostedtoolcache/julia/1.10.0/x64/share/julia/stdlib/v1.10/Distributed/src/process_messages.jl:121

Is this an expected error? It's happening everywhere. If it's expected, that should be made much clearer, if not, why is this not fatal?

[giordano]

Seems to have been introduced by #15, this was already happening in https://github.com/JuliaTesting/ParallelTestRunner.jl/actions/runs/18465435203/job/52606200030, last build of that PR. CC @maleadt

[maleadt]

Yes, that's expected. It's Distributed.jl complaining loudly (without a way to catch those messages, AFAIU) about the worker disappearing. Which I do by having it abort(), in order to detect that we handle crashing workers.

[vchuravy]

Yeah the error is printed from the errormonitor handler https://github.com/JuliaLang/julia/blob/c171ddb91de8acffb270f364b650a7708a840c38/base/task.jl#L733

Used in https://github.com/JuliaLang/Distributed.jl/blob/661112ef29b8d371b8612b94a629c0bbcf3d36f7/src/process_messages.jl#L121

Not sure if there is anything we can do, besides capturing stderr

[maleadt]

I've added a print statement surrounding the error to indicate it's expected.