Steps to reproduce

• Try to execute the spack buildcache push command to upload all the built packages to a private gitlab container registry
• Command fails with unauthorized error as shown below:
• 
• The mirror for the cache is setup as follows (the ${variables} contain sensitive information, hence kept them as $vars!):
• 

Note: Could not find the GitLab container registry usage information in the docs section. I assume, this must be the right way to define the mirror for gitlab container registry via OCI scheme, if not please advice the right usage! I have an associated GitLab token, which is been used also used along with the username as the combination for the defined access_pair.

Error message

No response

Information on your system

• Spack: 0.22.2 (594a376)
• Python: 3.8.10
• Platform: linux-ubuntu20.04-icelake
• Concretizer: clingo

General information

• I have run spack debug report and reported the version of Spack/Python/Platform
• I have searched the issues of this repo and believe this is not a duplicate
• I have run the failing commands in debug mode and reported the output