toga support subprocess?

[Jzhenli]

Hi, I try to run toga with huey (a lightweight task queue lib), and start the huey_consumer via subprocess in the toga startup function, it seems work when run briefcase dev, but after briefcase package will raise FileNotFoundError. Below is my example code,
hueytest.zip

BTW, my pc os is win11.

[freakboy3742]

Toga doesn't provide any support for subprocesses - Toga is a GUI toolkit.

Any subprocess support is provided by the underlying Python libraries; and in the case of Briefcase, can be influenced by the packaging process.

If you have a subprocess that is working fine under briefcase dev, but is raising a FileNotFoundError under a packaged app, the likely cause is that you're using a relative path to identify your subprocess binary. If you're explicitly naming an executable as part of a subprocess call, you need to provide a fully qualified path when naming that binary. You can use toga's paths attribute to build an absolute path.

There are also restrictions on some platforms. When running under briefcase dev, sys.executable is a Python interpreter. When running on desktop platforms, sys.executable becomes the stub binary that starts your app - and that binary isn't a standard Python interpreter. This inhibits some forms of multiprocessing, as you can't run sys.executable to start a new Python process.

On Mobile, you can't use subprocesses at all, because those platforms have a different process model.