tests: adjust to the new format in pyflakes output According to the pyflakes' NEWS.rst, the default output format changed recently: 2.2.0 (2020-04-08) - Include column information in error messages So the lines now read: contrib/perf.py:149:15 undefined name 'xrange' mercurial/hgweb/server.py:427:13 undefined name 'reload' mercurial/util.py:2862:24 undefined name 'file' Differential Revision: https://phab.mercurial-scm.org/D8618

tests: consistently use pyflakes as a Python module We check availability of pyflakes as a module, and also running it for real as a module. Only fair to test filterpyflakes.py working correctly when using pyflakes as a module too. Differential Revision: https://phab.mercurial-scm.org/D8617

heptapod-ci: also run tests for chg on python 2 I am not aware of any regular effort to run test with chg. So let's at least do it here. Differential Revision: https://phab.mercurial-scm.org/D8178

rust-dependencies: upgrade `micro-timer` dependency I wanted to to a tour of dependencies to upgrade, but only `micro-timer` has a new release which does not print when the function panics, which should be less misleading. Differential Revision: https://phab.mercurial-scm.org/D8605

context: fix creation of ProgrammingError to not use non-existent field Differential Revision: https://phab.mercurial-scm.org/D8606

help: explain in `hg help flags` that unambiguous prefixes are allowed I used `hg commit --amend` as an example because that's the most frequently used flag I could think of that doesn't yet have a short form. Differential Revision: https://phab.mercurial-scm.org/D8607

git: add coverage for manifest.diff() so we don't regress