depthcache: ignore permission and OS errors when writing
This cache is related to the obshashrange one and we update it lazily by
default.
This can be an issue when pulling locally from a read only repository that was
not configured for a more aggressive cache warming. The raised permission error
was uncaught and could crash the whole process. Errors during Cache update
should not block Mercurial operations.
#require test-repo pyflakes
Copied from Mercurial core (60ee2593a270)
$ cd "`dirname "$TESTDIR"`"
run pyflakes on all tracked files ending in .py or without a file ending
(skipping binary file random-seed)
$ hg locate 'set:(**.py or grep("^#!.*python")) - removed()' 2>/dev/null \
> | xargs pyflakes 2>/dev/null