Ctrl-C broken – repeating Ctrl-C required on Julia 1.8

[fonsp]

Since Julia 1.8, a single Ctrl-C does not work. I always need to repeat Ctrl-C multiple times to get the forced SIGINT (with WARNING: Force throwing a SIGINT):

Schermopname.2022-09-05.om.12.21.45.mov

I found this to be the case for anything that I interrupt, not just sleep. This means that, to exit Pluto, Jupyter, a web server or any other long running process, users will now need to hold down Ctrl-C, printing multiple WARNINGs, which makes Julia look unstable.

Julia Version 1.8.0
Commit 5544a0fab76 (2022-08-17 13:38 UTC)
Platform Info:
  OS: macOS (x86_64-apple-darwin21.4.0)
  CPU: 8 × Apple M1
  WORD_SIZE: 64
  LIBM: libopenlibm
  LLVM: libLLVM-13.0.1 (ORCJIT, westmere)
  Threads: 1 on 8 virtual cores

Julia Version 1.7.0
Commit 3bf9d17731 (2021-11-30 12:12 UTC)
Platform Info:
  OS: macOS (x86_64-apple-darwin19.5.0)
  CPU: Apple M1
  WORD_SIZE: 64
  LIBM: libopenlibm
  LLVM: libLLVM-12.0.1 (ORCJIT, westmere)

Same problem with the MacOS ARM build.

[pankgeorg]

I can confirm I have the same issue on Windows 11 on an Intel processor and Windows Terminal 1.15.2203.0

Windows 11 Pro Insider Preview Build 25193.rs_prelease.220829-1428 (no legacy cmd, unfortunately!)

julia> versioninfo()
Julia Version 1.8.0
Commit 5544a0fab7 (2022-08-17 13:38 UTC)
Platform Info:
  OS: Windows (x86_64-w64-mingw32)
  CPU: 8 × 11th Gen Intel(R) Core(TM) i7-1165G7 @ 2.80GHz
  WORD_SIZE: 64
  LIBM: libopenlibm
  LLVM: libLLVM-13.0.1 (ORCJIT, tigerlake)
  Threads: 1 on 8 virtual cores

[benz0li]

Debian 11 (bullseye), amd64, JupyterLab Terminal:

julia> versioninfo()
Julia Version 1.8.0
Commit 5544a0fab76 (2022-08-17 13:38 UTC)
Platform Info:
  OS: Linux (x86_64-linux-gnu)
  CPU: 40 × Intel(R) Xeon(R) Silver 4210R CPU @ 2.40GHz
  WORD_SIZE: 64
  LIBM: libopenlibm
  LLVM: libLLVM-13.0.1 (ORCJIT, cascadelake)
  Threads: 1 on 40 virtual cores
Environment:
  JULIA_VERSION = 1.8.0
  JULIA_PATH = /opt/julia

julia> sleep(123)
^C^C^C^C^C^C^C^C^CWARNING: Force throwing a SIGINT
ERROR: InterruptException:
Stacktrace:
 [1] poptask(W::Base.InvasiveLinkedListSynchronized{Task})
   @ Base ./task.jl:921
 [2] wait()
   @ Base ./task.jl:930
 [3] wait(c::Base.GenericCondition{Base.Threads.SpinLock})
   @ Base ./condition.jl:124
 [4] _trywait(t::Timer)
   @ Base ./asyncevent.jl:138
 [5] wait
   @ ./asyncevent.jl:155 [inlined]
 [6] sleep(sec::Int64)
   @ Base ./asyncevent.jl:240
 [7] top-level scope
   @ REPL[2]:1

julia> 

Debian 11 (bullseye), arm64, JupyterLab Terminal:

julia> versioninfo()
Julia Version 1.8.0
Commit 5544a0fab76 (2022-08-17 13:38 UTC)
Platform Info:
  OS: Linux (aarch64-linux-gnu)
  CPU: 8 × unknown
  WORD_SIZE: 64
  LIBM: libopenlibm
  LLVM: libLLVM-13.0.1 (ORCJIT, generic)
  Threads: 1 on 8 virtual cores
Environment:
  JULIA_VERSION = 1.8.0
  JULIA_PATH = /opt/julia

julia> sleep(123)
^C^C^C^C^C^C^C^C^CWARNING: Force throwing a SIGINT
ERROR: InterruptException:
Stacktrace:
 [1] poptask(W::Base.InvasiveLinkedListSynchronized{Task})
   @ Base ./task.jl:921
 [2] wait()
   @ Base ./task.jl:930
 [3] wait(c::Base.GenericCondition{Base.Threads.SpinLock})
   @ Base ./condition.jl:124
 [4] _trywait(t::Timer)
   @ Base ./asyncevent.jl:138
 [5] wait
   @ ./asyncevent.jl:155 [inlined]
 [6] sleep(sec::Int64)
   @ Base ./asyncevent.jl:240
 [7] top-level scope
   @ REPL[2]:1

julia> 

ℹ️ May be reproduced at https://demo.jupyter.b-data.ch or with docker run --rm -it -p 8888:8888 registry.gitlab.b-data.ch/jupyterlab/julia/pubtools

[gbaraldi]

A bisect shows that the first bad commit is 0eaf35a .
@vtjnash

[fonsp]

It looks like it is still possible to interrupt Pkg precompilation with a single Ctrl+C (video), strange...

[fonsp]

Narrowing down on the interrupt in Pkg precompilation, I found that Ctrl+C still works reliably in this snippet:

while true
	sleep(.1)
end

Details

julia> sleep(100)
^C^C^C^C^C^C^CWARNING: Force throwing a SIGINT
ERROR: InterruptException:

julia> while true
       sleep(100)
       end
^C^C^C^C^C^C^C^CWARNING: Force throwing a SIGINT
ERROR: InterruptException:

julia> while true
       sleep(.1)
       end
^CERROR: InterruptException:
Stacktrace:
 [1] poptask(W::Base.InvasiveLinkedListSynchronized{Task})
   @ Base ./task.jl:921
 [2] wait()
   @ Base ./task.jl:930
 [3] wait(c::Base.GenericCondition{Base.Threads.SpinLock})
   @ Base ./condition.jl:124
 [4] _trywait(t::Timer)
   @ Base ./asyncevent.jl:138
 [5] wait
   @ ./asyncevent.jl:155 [inlined]
 [6] sleep(sec::Float64)
   @ Base ./asyncevent.jl:240
 [7] top-level scope
   @ ./REPL[14]:2

julia> 

This means that Packages that use the "Press Ctrl+C to stop" UI, like an HTTP.jl server, can use this as a workaround.

Example with HTTP.jl:

Instead of:

server = HTTP.serve!(...)

@info "Server running, press Ctrl+C to interrupt..."
wait(server)

You can use:

server = HTTP.serve!(...)

@info "Server running, press Ctrl+C to interrupt..."
try
	while Base.isopen(server)
		sleep(.1)
	end
catch e
	@info "Closing server..."
	close(server)
	wait(server)
end