got the exact same output as you.
createrepo_c version 0.17.1-1.el7
however - I’ve just found that i have tfm-rubygem-pulp_2to3_migration_client-0.11.0-1.el7.noarch installed, while at a quick glance, it looks like the zck fix is was pushed to milestone 0.11.1, not sure if i somehow have an out-of-date package there or if it was backported
And I think I forgot to run the migration-reset before retrying… Coming back to this after holiday break and doing things right the first time is hard…
Will report back if reset and rerun gets me through this. Thanks for all the help thus far.
Problem appears to have been my holiday fog forgetting to run the migration-reset.
After running that and rerunning the prepare step it ended with some corrupt rpms - after fixing that and rerunning it finally finished.
Currently running switchover, then it’s just upgrade time!