Library went missing and cannot be re-initialized

[Igor]

So, the problem as it stands today:
1. I remove my library (including track metadata) and reboot Mixxx
2. Mixxx asks me to add a library on startup
3. Mixxx finishes booting, and displays 4 of >10k tracks; even those 4 cannot be played

I can continue reproducing this indefinitely. This is what I see in the logs:

Debug [LibraryScanner 1]: upgrade filename is "/home/igor47/.mixxx/DBUPGRADED"
Debug [LibraryScanner 1]: Committing transaction on "LIBRARY_SCANNER" result: true
Debug [LibraryScanner 1]: Legacy importer took 0 ms
Debug [LibraryScanner 1]: Recursively scanning library.
Debug [LibraryScanner 1]: LibraryScanner::slotFinishHashedScan
Debug [LibraryScanner 1]: src/library/dao/libraryhashdao.cpp 76 FAILED QUERY [ "INSERT INTO LibraryHashes (directory_path, hash, directory_deleted) VALUES (?, ?, ?)" ] QSqlError(19, "Unable to fetch row", "UNIQUE constraint failed: LibraryHashes.directory_path") Creating new dirhash failed.
Debug [LibraryScanner 1]: LibraryScanner::slotFinishUnhashedScan
Debug [LibraryScanner 1]: Recursive scanning finished cleanly.
Debug [LibraryScanner 1]: Committing transaction on "LIBRARY_SCANNER" result: true
Debug [LibraryScanner 1]: Marking tracks in changed directories as verified
Debug [LibraryScanner 1]: Marking unchanged directories and tracks as verified
Debug [LibraryScanner 1]: Checking remaining unverified tracks.
Debug [LibraryScanner 1]: Marking unverified tracks as deleted.
Debug [LibraryScanner 1]: Marking unverified directories as deleted.
Debug [LibraryScanner 1]: Detecting moved files.
Debug [LibraryScanner 1]: Committing transaction on "LIBRARY_SCANNER" result: true
Debug [LibraryScanner 1]: Detecting cover art for unscanned files.
Debug [LibraryScanner 1]: Scan finished cleanly
Debug [LibraryScanner 1]: Scan took: 362886128 ns. 1939 unchanged directories. 1 changed/added directories. 0 tracks verified from changed/added directories. 3 new tracks.

I'm not exactly sure how I got into this state. I re-linked my library (from an SD card to my laptop's internal drive) but it seemed to work fine after that. There was a crash on exit (mixxx went defunct) and I force-killed it, and when it came back up all of my tracks were in the 'missing tracks' list and i couldn't get them back. I figured I would just nuke it and start over, and now I'm in this odd state.

This is on Fedora 23, using Mixxx 2.0.0.

[Igor (igor47)]

i renamed `mixxxdb.sqlite` to `mixxxdb.sqlite.bak` and now it's re-scanning my library properly. I'll attach the backed up, messed-up SQLite db to the ticket in case anyone is curious about exactly how it got messed up.

[Uwe Klotz (uklotzde-deactivatedaccount)]

This issue is caused by database inconsistencies that will hopefully be fixed soon:

https://bugs.launchpad.net/mixxx/+bug/1846945

[Uwe Klotz (uklotzde-deactivatedaccount)]

Not fixed, only a workaround:
https://github.com/mixxxdj/mixxx/pull/2321

[Swiftb0y (swiftb0y)]

Mixxx now uses GitHub for bug tracking. This bug has been migrated to:
https://github.com/mixxxdj/mixxx/issues/8595