Modern Mercurial may emit some more patterns under "--debug".

This whole list is gross and can likely now be eliminated by increasing the minimum required Mercurial version (as arc has), but just paper over it for now.

Locally, saw some views return to functional behavior that weren't previously working on a modern version of Mercurial.

The reproduction case is likely something in the vein of "repository is not writable by webserver, look at history view".