PSA: RPM database issues after update to libdb-5.3.28-21 on Fedora 24 and Fedora 25

Hi there, folks!

This is an important PSA for Fedora 24, 25 and 26 (pre-release) users. tl;dr version: if you recently updated and got some kind of error or crash and now you're getting RPM database errors, you need to do the old reliable RPM database fix dance:

# rm -f /var/lib/rpm/__db*
# rpm --rebuilddb

and all should be well again. We do apologize for this.

Longer version: there's a rather subtle and tricky bug in libdb (the database that RPM uses) which has been causing problems with upgrades from Fedora 24/25 to Fedora 26. The developers have made a few attempts to fix this, and testing this week had indicated that the most recent attempt - libdb-5.3.28-21 - was working well. We believed the fix needed to be applied both on the 'from' and the 'to' end of any affected transaction, so we went ahead and sent the -21 update out to Fedora 24, 25 and 26.

Unfortunately it now seems like -21 may still have bugs that were not found in the testing; in the last few hours several people have reported that they hit some kind of crash during an update involving libdb -21, and subsequently there was a problem with their RPM database.

While we investigate and figure out what to do about fixing this properly, in the short term, if you're affected, just doing the old "rebuild the RPM database" trick seems to resolve the problem:

# rm -f /var/lib/rpm/__db*
# rpm --rebuilddb

EDIT: Update 2017-06-13: We briefly sent a -22 build to updates-testing for 24, 25 and 26 with the fixes reverted. It turns out that updating from -21 to -22 can, again, cause the same kinds of problem, which can be resolved in the same way. We've removed the -22 update now and are sticking with -21, and will just be advising affected people to rebuild their databases if they hit database issues. Note that if you updated from -21 to -22 while it was in updates-testing, that update may also have caused database issues, which can be resolved in the same way; and when you update from -22 to -23 or later, the same may happen again.

It's unfortunate that we have to break that one out of cold storage (I hadn't had to do it for so long I'd almost forgotten it...), but it should at least get you back up and working for now.

We do apologize sincerely for this mess, and we'll try and do all we can to fix it up ASAP.