Crash on status_bar.statusItemWithLength_

[lezgomatt]

Describe the bug

The following code:

status_bar = NSStatusBar.systemStatusBar()
status_item = status_bar.statusItemWithLength_(NSVariableStatusItemLength)

crashes with the error:

-[_NSViewBackingLayer NS_setView:]: unrecognized selector sent to instance 0x600003e43ed0

The app terminates terminated by signal SIGTRAP (Trace or breakpoint trap) or for some illegal hardware instruction.

Platform information

• Python version: Python 3.10.5
• How was python installed: nix
• macOS version: Ventura

To Reproduce

See description above.

Expected behavior

It should work, and not crash.

Additional context

• This worked on pyobjc v8 (and maybe earlier). It broke on v9, and is still broken for v10.
• zsh: illegal hardware instruction ezntfs-app lezgomatt/ezntfs#10
• https://github.com/lezgomatt/ezntfs/blob/0291beaf4bbdbab208626662e885ad338d563ad6/ezntfs/app.py#L73

[ronaldoussoren]

This is most likely not a bug in PyObjC, but Cocoa being annoyingly crash prone when using GUI code when the app isn't initialised fully enough.

from Cocoa import NSStatusBar, NSVariableStatusItemLength, NSApplication

NSApplication.sharedApplication()
status_bar = NSStatusBar.systemStatusBar()
status_item = status_bar.statusItemWithLength_(NSVariableStatusItemLength)
print(f"{status_item=}")

This script works on my system (macOS 14.3.1, M1 laptop), but crashes with Assertion failed: (CGAtomicGet(&is_initialized)), function CGSConnectionByID, file CGSConnection.mm, line 419. when I leave out the call to NSApplication.sharedApplication().

What the context in which the code is called?

[lezgomatt]

Hi @ronaldoussoren, thanks for sharing that snippet! I can confirm that your snippet works on my machine as well. It looks like my issue is related to how I imported the library (but the error doesn't occur on import). The following snippet breaks:

from Foundation import *
from AppKit import *

NSApplication.sharedApplication()
status_bar = NSStatusBar.systemStatusBar()
status_item = status_bar.statusItemWithLength_(NSVariableStatusItemLength)
print(f"{status_item=}")

FWIW it works on v8. Replacing import * with the specific imports fixes the issue (and speed things up too).