tests: demonstrate how evolve loses transitive copies when interrupted
Let's say `b` has been renamed to `c` in commit A and then renamed
to `d` in commit B. We now modify A in a way that will cause a
conflict when we evolve B. `hg evolve` will now stop and let the user
resolve the conflicts, but it will have lost the copy information in
the working copy (should still be c->d).
#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 -I 'set:(**.py or grep("^#!.*python")) - removed()' 2>/dev/null \
> | xargs pyflakes 2>/dev/null