CoLic throwing path error

[altsalt]

Hello, I am participating in the MSR Hackathon and have attempted to install Graal a few times to no avail. Most recently, I set up a clean Debian 11 VM to verify that it wasn't due to prior system configuration, incorrect permissions, etc. Alas, the same error is appearing:

Python 3.9.2 (default, Feb 28 2021, 17:03:44) 
[GCC 10.2.1 20210110] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> from graal.backends.core.colic import CoLic
>>> repo_uri = 'https://github.com/chaoss/grimoirelab-graal'
>>> repo_dir = 'grimoirelab-graal'
>>> cl = CoLic(uri=repo_uri, git_path=repo_dir)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/local/lib/python3.9/dist-packages/graal-0.2.9-py3.9.egg/graal/backends/core/colic.py", line 79, in __init__
    if not GraalRepository.exists(exec_path):
  File "/usr/local/lib/python3.9/dist-packages/graal-0.2.9-py3.9.egg/graal/graal.py", line 411, in exists
    return os.path.exists(dest)
  File "/usr/lib/python3.9/genericpath.py", line 19, in exists
    os.stat(path)
TypeError: stat: path should be string, bytes, os.PathLike or integer, not NoneType
>>> 

I have tried with both a blank directory and having pre-created the grimoirelab-graal folder (not that this should be a blocker, but looking for anything that might be...)

Any pointers or guidance would be very much appreciated. Thanks!