I know it used to work before, but currently I can’t get distributed computing on remote machines working again.
If I simply run
using Distributed
addprocs(["<remotename>"], exename="<pathToRemoteJuliaExe>", dir="<pathToRemoteHomeDir>")
@fetch myid()
like in the Distributed doc, I receive
ERROR: On worker 2:
TypeError: non-boolean (Nothing) used in boolean context
Stacktrace:
[1] deserialize
@ /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.7/Serialization/src/Serialization.jl:1166
[2] handle_deserialize
@ /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.7/Serialization/src/Serialization.jl:947
[3] deserialize
@ /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.7/Serialization/src/Serialization.jl:801 [inlined]
[4] deserialize
@ /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.7/Serialization/src/Serialization.jl:1018
[5] handle_deserialize
@ /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.7/Serialization/src/Serialization.jl:947
[6] deserialize_fillarray!
@ /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.7/Serialization/src/Serialization.jl:1230
[7] deserialize_array
@ /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.7/Serialization/src/Serialization.jl:1222
[8] handle_deserialize
@ /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.7/Serialization/src/Serialization.jl:852
[9] deserialize
@ /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.7/Serialization/src/Serialization.jl:801 [inlined]
[10] deserialize_typename
@ /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.7/Serialization/src/Serialization.jl:1296
[11] deserialize
@ /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.7/Distributed/src/clusterserialize.jl:68
[12] handle_deserialize
@ /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.7/Serialization/src/Serialization.jl:947
[13] deserialize
@ /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.7/Serialization/src/Serialization.jl:801
[14] handle_deserialize
@ /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.7/Serialization/src/Serialization.jl:858
[15] deserialize
@ /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.7/Serialization/src/Serialization.jl:801
[16] handle_deserialize
@ /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.7/Serialization/src/Serialization.jl:861
[17] deserialize
@ /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.7/Serialization/src/Serialization.jl:801 [inlined]
[18] deserialize_msg
@ /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.7/Distributed/src/messages.jl:87
[19] #invokelatest#2
@ ./essentials.jl:716 [inlined]
[20] invokelatest
@ ./essentials.jl:714 [inlined]
[21] message_handler_loop
@ /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.7/Distributed/src/process_messages.jl:169
[22] process_tcp_streams
@ /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.7/Distributed/src/process_messages.jl:126
[23] #99
@ ./task.jl:423
Stacktrace:
[1] #remotecall_fetch#143
@ /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.6/Distributed/src/remotecall.jl:394 [inlined]
[2] remotecall_fetch(::Function, ::Distributed.Worker)
@ Distributed /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.6/Distributed/src/remotecall.jl:386
[3] remotecall_fetch(::Function, ::Int64; kwargs::Base.Iterators.Pairs{Union{}, Union{}, Tuple{}, NamedTuple{(), Tuple{}}})
@ Distributed /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.6/Distributed/src/remotecall.jl:421
[4] remotecall_fetch(::Function, ::Int64)
@ Distributed /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.6/Distributed/src/remotecall.jl:421
[5] top-level scope
@ none:1
If I just add local workers by addprocs(2), everything works as expected. Also, @spawn alone raises no error, it is the fetch that triggers it.
I don’t really expect anyone to be able to reproduce this error since this seems like the absolute fundamental use of distributed computing. But maybe someone has an idea what the source of the issue could be? Is it worth updating to 1.7 on my host to match the version on the remote computer?
UPDATE:
Indeed, switching to Julia 1.7.2 on my host got rid of the error. I reported this in the Julia repo.