Relaunching packaged macOS app on Catalina doesn't bring its UI to the front

[tmontes]

See the second segment of this comment, quoted here for simplicity:

However, this strategy of using a shell (or Python or Ruby) "launcher", while a popular trick that worked in the past, seems to be breaking down on more recent macOS releases, particularly catalina. See this blog post about how one Emacs mac build's too-clever binary-selector launching script effectively broke the ability to launch the application multiple times. puppy.app seems to have the same problem - launching it from the Downloads folder while it's open doesn't bring it back to the front. By contrast, py2app applications use an executable shim and do not have this problem, since they don't re-exec; testing with my own pygame apps validates this. So you might want to figure out some way to build a C executable that invokes Python as a library.