Gstreamer/PyGObject breaks SIGINT handling

GLib.MainLoop.__init__ installs a SIGINT handler which calls GLib.MainLoop.quit(), and then reraise a KeyboardInterrupt in that thread. However, the main thread will not notice that, and continues whatever it is doing, which mostly means that it will hang as it is waiting for something. What you would want is a KeyboardInterrupt in the main thread, as this is the original behavior when you press Ctrl+C.

I came up with this workaround / ugly monkey patch to just disable the SIGINT handler. However, a better fix would be in PyGObject to raise the KeyboardInterrupt in the main thread.

def monkeyfix_glib():
  """
  Fixes some stupid bugs such that SIGINT is not working.
  This is used by audioread, and indirectly by librosa for loading audio.
  https://stackoverflow.com/questions/16410852/
  """
  try:
    import gi
  except ImportError:
    return
  try:
    from gi.repository import GLib
  except ImportError:
    from gi.overrides import GLib
  # Do nothing.
  # The original behavior would install a SIGINT handler which calls GLib.MainLoop.quit(),
  # and then reraise a KeyboardInterrupt in that thread.
  # However, we want and expect to get the KeyboardInterrupt in the main thread.
  GLib.MainLoop.__init__ = lambda *args, **kwargs: None

[lazka]

fyi, pygobject 3.28+ will no longer install a signal handler there if one was already set before and will no longer change anything when not run in the main thread.

There is an easier fix to work around all this:

instead of GLib.MainLoop() do GLib.MainLoop.new(None, False) in audioread

[sampsyo]

Got it; thanks again for the background about how this happened!