Also, test suites in the original tokudb (from tokutek and now from percona) have dots in the name, so I was renaming them during the merge. If you want to fix mtr instead, we could rename suites back and have a bit simple tokudb merge afterwards.

I would like to fix it in MTR, yes, but if we want to allow dots both in suite names and test names, there will always be an ambiguity – like, in tokudb.backup.backup_master_info, should it be suite=tokudb test=backup.backup_master_info or suite=tokudb.backup test=backup_master_info?

Strangely, it still doesn't seem to work in Percona server, on some other reason, even though they allow more dots in the names than we do. I'm not sure how they deal with that internally.

But on top of the dot problem, our version of MTR also cannot manage dashes in the suite name, apparently because it expects the part after the dash to indicate an overlay.