Skip to content

Resuming python -m asyncio process is not properly handled on Unix-like platforms #139391

Closed
Closed
Resuming python -m asyncio process is not properly handled on Unix-like platforms#139391
Labels
3.13only security fixes3.14bugs and security fixes3.15bugs and security fixesOS-linuxOS-macstdlibStandard Library Python modules in the Lib/ directorytopic-replRelated to the interactive shelltype-bugAn unexpected behavior, bug, or error

Description

@yihong0618
yihong0618
opened on Sep 28, 2025

Bug report

Bug description:

The resumed REPL can't be exited on Unix-like platforms other than through kill:

./python.exe -m asyncio
ctrl + z
fg
# then the terminal boom

>>> 
Traceback (most recent call last):
  File "/Users/hyi/.local/share/uv/python/cpython-3.14.0rc2-macos-aarch64-none/lib/python3.14/_pyrepl/readline.py", line 395, in multiline_input
    return reader.readline()
           ~~~~~~~~~~~~~~~^^
  File "/Users/hyi/.local/share/uv/python/cpython-3.14.0rc2-macos-aarch64-none/lib/python3.14/_pyrepl/reader.py", line 752, in readline
    self.restore()
    ~~~~~~~~~~~~^^
  File "/Users/hyi/.local/share/uv/python/cpython-3.14.0rc2-macos-aarch64-none/lib/python3.14/_pyrepl/reader.py", line 608, in restore
    self.console.restore()
    ~~~~~~~~~~~~~~~~~~~~^^
  File "/Users/hyi/.local/share/uv/python/cpython-3.14.0rc2-macos-aarch64-none/lib/python3.14/_pyrepl/unix_console.py", line 377, in restore
    signal.signal(signal.SIGWINCH, self.old_sigwinch)
    ~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/hyi/.local/share/uv/python/cpython-3.14.0rc2-macos-aarch64-none/lib/python3.14/signal.py", line 58, in signal
    handler = _signal.signal(_enum_to_int(signalnum), _enum_to_int(handler))
ValueError: signal only works in main thread of the main interpreter
>>> 
Traceback (most recent call last):
  File "/Users/hyi/.local/share/uv/python/cpython-3.14.0rc2-macos-aarch64-none/lib/python3.14/_pyrepl/readline.py", line 395, in multiline_input
    return reader.readline()
           ~~~~~~~~~~~~~~~^^
  File "/Users/hyi/.local/share/uv/python/cpython-3.14.0rc2-macos-aarch64-none/lib/python3.14/_pyrepl/reader.py", line 752, in readline
    self.restore()
    ~~~~~~~~~~~~^^
  File "/Users/hyi/.local/share/uv/python/cpython-3.14.0rc2-macos-aarch64-none/lib/python3.14/_pyrepl/reader.py", line 608, in restore
    self.console.restore()
    ~~~~~~~~~~~~~~~~~~~~^^
  File "/Users/hyi/.local/share/uv/python/cpython-3.14.0rc2-macos-aarch64-none/lib/python3.14/_pyrepl/unix_console.py", line 377, in restore
    signal.signal(signal.SIGWINCH, self.old_sigwinch)
    ~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/hyi/.local/share/uv/python/cpython-3.14.0rc2-macos-aarch64-none/lib/python3.14/signal.py", line 58, in signal
    handler = _signal.signal(_enum_to_int(signalnum), _enum_to_int(handler))
ValueError: signal only works in main thread of the main interpreter
>>>
Image

CPython versions tested on:

CPython main branch

Operating systems tested on:

macOS

Linked PRs

Activity

  1. yihong0618
    added
    type-bugAn unexpected behavior, bug, or error
    on Sep 28, 2025
  2. picnixz
    added
    OS-mac
    stdlibStandard Library Python modules in the Lib/ directory
    topic-replRelated to the interactive shell
    on Sep 28, 2025

  3. yihong0618 commented on Sep 29, 2025

    @yihong0618
    yihong0618
    on Sep 29, 2025
    ContributorAuthor

    update

    linux can also have this problem

    ./python -m asyncio
>>> 
Traceback (most recent call last):
  File "/home/hyi/cpython/Lib/_pyrepl/readline.py", line 395, in multiline_input
    return reader.readline()
           ~~~~~~~~~~~~~~~^^
  File "/home/hyi/cpython/Lib/_pyrepl/reader.py", line 752, in readline
    self.restore()
    ~~~~~~~~~~~~^^
  File "/home/hyi/cpython/Lib/_pyrepl/reader.py", line 608, in restore
    self.console.restore()
    ~~~~~~~~~~~~~~~~~~~~^^
  File "/home/hyi/cpython/Lib/_pyrepl/unix_console.py", line 393, in restore
    signal.signal(signal.SIGWINCH, self.old_sigwinch)
    ~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/hyi/cpython/Lib/signal.py", line 58, in signal
    handler = _signal.signal(_enum_to_int(signalnum), _enum_to_int(handler))
ValueError: signal only works in main thread of the main interpreter
>>> 
Traceback (most recent call last):
  File "/home/hyi/cpython/Lib/_pyrepl/readline.py", line 395, in multiline_input
    return reader.readline()
           ~~~~~~~~~~~~~~~^^
  File "/home/hyi/cpython/Lib/_pyrepl/reader.py", line 752, in readline
    self.restore()
    ~~~~~~~~~~~~^^
  File "/home/hyi/cpython/Lib/_pyrepl/reader.py", line 608, in restore
    self.console.restore()
    ~~~~~~~~~~~~~~~~~~~~^^
  File "/home/hyi/cpython/Lib/_pyrepl/unix_console.py", line 393, in restore
    signal.signal(signal.SIGWINCH, self.old_sigwinch)
    ~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/hyi/cpython/Lib/signal.py", line 58, in signal
    handler = _signal.signal(_enum_to_int(signalnum), _enum_to_int(handler))
ValueError: signal only works in main thread of the main interpreter
>>> 
Traceback (most recent call last):
  File "/home/hyi/cpython/Lib/_pyrepl/readline.py", line 395, in multiline_input
    return reader.readline()
           ~~~~~~~~~~~~~~~^^
  File "/home/hyi/cpython/Lib/_pyrepl/reader.py", line 752, in readline
    self.restore()
    ~~~~~~~~~~~~^^
  File "/home/hyi/cpython/Lib/_pyrepl/reader.py", line 608, in restore
    self.console.restore()
    ~~~~~~~~~~~~~~~~~~~~^^
  File "/home/hyi/cpython/Lib/_pyrepl/unix_console.py", line 393, in restore
    signal.signal(signal.SIGWINCH, self.old_sigwinch)
    ~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/hyi/cpython/Lib/signal.py", line 58, in signal
    handler = _signal.signal(_enum_to_int(signalnum), _enum_to_int(handler))
ValueError: signal only works in main thread of the main interpreter
>>> 
Traceback (most recent call last):
  File "/home/hyi/cpython/Lib/_pyrepl/reader.py", line 748, in readline
    self.handle1()
    ~~~~~~~~~~~~^^
  File "/home/hyi/cpython/Lib/_pyrepl/reader.py", line 731, in handle1
    self.do_cmd(cmd)
    ~~~~~~~~~~~^^^^^
  File "/home/hyi/cpython/Lib/_pyrepl/reader.py", line 656, in do_cmd
    command.do()
    ~~~~~~~~~~^^
  File "/home/hyi/cpython/Lib/_pyrepl/commands.py", line 430, in do
    raise EOFError
EOFError

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/home/hyi/cpython/Lib/_pyrepl/readline.py", line 395, in multiline_input
    return reader.readline()
           ~~~~~~~~~~~~~~~^^
  File "/home/hyi/cpython/Lib/_pyrepl/reader.py", line 752, in readline
    self.restore()
    ~~~~~~~~~~~~^^
  File "/home/hyi/cpython/Lib/_pyrepl/reader.py", line 608, in restore
    self.console.restore()
    ~~~~~~~~~~~~~~~~~~~~^^
  File "/home/hyi/cpython/Lib/_pyrepl/unix_console.py", line 393, in restore
    signal.signal(signal.SIGWINCH, self.old_sigwinch)
    ~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/hyi/cpython/Lib/signal.py", line 58, in signal
    handler = _signal.signal(_enum_to_int(signalnum), _enum_to_int(handler))
ValueError: signal only works in main thread of the main interpreter
>>> Terminated
[hyi@rocky cpython]$ ^C
[hyi@rocky cpython]$ uname -a
Linux rocky 6.15.11-orbstack-00539-g9885ebd8e3f4 #1 SMP PREEMPT Fri Aug 22 08:24:56 UTC 2025 aarch64 aarch64 aarch64 GNU/Linux
  4. picnixz
    changed the title [-]python -m asyncio then Ctrl + z then fg will break the repl and raise error forever[/-] [+]Resuming `python -m asyncio` process is not properly handled[/+] on Sep 29, 2025
  5. picnixz
    added
    OS-linux
    on Sep 29, 2025
  6. picnixz
    changed the title [-]Resuming `python -m asyncio` process is not properly handled[/-] [+]Resuming `python -m asyncio` process is not properly handled on Unix-like platforms[/+] on Sep 29, 2025
  7. picnixz
    added
    3.13only security fixes
    3.14bugs and security fixes
    3.15bugs and security fixes
    on Sep 29, 2025
  8. kumaraditya303
    added a commit that references this issue on Oct 9, 2025

    gh-139391: properly handle `signal.signal()` in `UnixConsole` when ca…

    b8c8b8f
  9. kumaraditya303
    closed this as completedon Oct 9, 2025
  10. ambv
    added a commit that references this issue on Oct 9, 2025

    [3.13] pythongh-139391: properly handle `signal.signal()` in `UnixCon…

    d693b03
  11. miss-islington
    added a commit that references this issue on Oct 9, 2025

    pythongh-139391: properly handle `signal.signal()` in `UnixConsole` w…

    fd3773d
  12. kumaraditya303
    added 2 commits that reference this issue on Oct 9, 2025

    [3.14] gh-139391: properly handle `signal.signal()` in `UnixConsole` …

    8761d6e

    [3.13] gh-139391: properly handle `signal.signal()` in `UnixConsole` …

    94ff4d4
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Metadata

Metadata

Assignees

No one assigned

    Labels

    3.13only security fixes3.14bugs and security fixes3.15bugs and security fixesOS-linuxOS-macstdlibStandard Library Python modules in the Lib/ directorytopic-replRelated to the interactive shelltype-bugAn unexpected behavior, bug, or error

    Projects

    No projects

      Milestone

      No milestone

      Relationships

      None yet

      Development

      No branches or pull requests

      Issue actions