Python applications provided by RH in RHEL should be hardened so they are not negatively impacted by custom python modules installed on system. Installing upstream initparse version 0.4.0 on RHEL breaks subscription-manager fundamentally. Try:

Reproducer:

# pip3.6 install iniparse==0.4 --ignore-installed
WARNING: Running pip install with root privileges is generally not a good idea. Try `pip3.6 install --user` instead.
Collecting iniparse==0.4
  Using cached https://files.pythonhosted.org/packages/0f/d1/3090ef9be165da5ddb1b0cf2b332d3282588bdd2dd0967e94b547f10055f/iniparse-0.4.tar.gz
Installing collected packages: iniparse
  Running setup.py install for iniparse ... done
Successfully installed iniparse-0.4

# subscription-manager 
Unable to find Subscription Manager module.
Error: No module named 'ini'

This is especially visible for systems upgrading between RHEL versions using leapp, where users could install specific python modules using pip for alternative python version (not the platform one) e.g. because of RHEL does not provide an RPM with such a python module for alternative versions of python. But this issue is generic and it is not limited to in-place upgrades - as shown in example above.

I expect that similar problems are for RHSM in RHEL 10 as well. Please update the shebang, using `-s` option (or -sP options rather) to load only system python modules.

Additional info:

• see the discussion in the original ticket with mhroncok@redhat.com and lbalhar@redhat.com for more information.
• Here is PR from mhroncok@redhat.com for RHSM in Fedora with the fix: https://src.fedoraproject.org/rpms/subscription-manager/pull-request/69