Marcin has not yet completed the FPCA as far as I can tell, and he's not in any vendor-specific CLA groups. As I understand things, that's going to be a requirement for packager access.

We'll fix that ASAP.

It doesn't look like this has been rectified yet.

It's been another week; is there some issue which prevents Marcin from accepting the FPCA? I hope there's no legal blocker here, bit I do see that there's a separate cla_intel group which some Fedora users with @intel.com addresses are in. (And some @intel.com folks are in the standard cla group and not that group.)

Yes, that's the reason. Initially we were told to not accept the FCPA, but to get into cla_intel instead.
However, the last instructions was to sign off the FCPA, so Marcin will do (or already did).

It wasn't there when I checked about 90 minutes ago but it's there now. I've taken care of the rest of the sponsorship process, so once the permissions propagate you should be able to add him as an additional maintainer in the pagure project.

Didn't check it for a while, but marcinslusarz still hasn't been added to the packagers group.
Is there still something missing on our side?

They are in the packager group.

if you are having trouble adding them on a package in src.fedoraproject.org, please have them login. Group memberships are synced at login time, so until they login after the group addition it will not know they are now in that group.