I am out of ideas what to try, so I am going to write one final post summarizing what I think we know:
- The error goes something like this: During sync, pulp creates a temp file, and when it tries to open the file it is not there (or lacking permissions).
- This consistently happens when syncing EPEL 8 from arbitrary mirror, but only on this one setup (others can’t seem to reproduce this).
- Other repos synced on the same setup are unaffected.
- It does not happen for “On Demand” sync, so the relevant file must be one that is not downloaded for on demand sync (most likely some RPM package from EPEL).
Given all of the above, the only thing I can think of is that there is some network issue that affects exactly one file from this one repository. You have said:
I remember a case where a firewall would let 99% of packages through without issue, but would do some kind of inspection of specific files, altering the checksum in the process. Maybe this is something like that?