I'm trying to access the progress of time consuming Git operations using GitPython. I tried the sample solution taken from the official documentation, and also tried passing in a method following the exact signature of the update method below. Everytime I call fetch(), push(), pull() with the parameter progress=<anything>, the programm is stuck and the update method does not get called. If I call those operations without setting the progress parameter, it works flawlessly.

• $ git --version is 2.21.0
• Calling sys.stdout.flush() after print() does not help either
• I use assert to assure my repo objects are available and in the expected state
• ProgressPrinter() yields not None
• I tried calling the functions from the main thread and multithreaded
• I took a look at the implementation (line 350) of RemoteProgress and also the implementation (line 815) of push() and do not see a reason, why it would not continue execution
• I found out, that when I assign my ProgressPrinter instance and pass the assigned variable, the programm is not stuck anymore. Yet the update() method does not get called and no progress is printed:

# Not stuck anymore, yet no progress
pp = ProgressPrinter()
fetch_info = origin.fetch(progress=pp)

Core of my implementation:

from git import RemoteProgress

class ProgressPrinter(RemoteProgress):
    def update(self,
               op_code,
               cur_count,
               max_count=None,
               message=''):
        print("Is this even called?")

And later on:

origin = repo.remotes.origin
assert origin.exists()
fetch_info = origin.fetch(progress=ProgressPrinter())

Any recommendations on how to investigate this problem furthermore? I've been debugging this for several days now and feel like I am missing something.