setup: raise minimum Python version to 2.7.4 On older Python versions, Mercurial is not really usable because of https://bugs.python.org/issue10211. Recently someone reported a crash on the mailing list when running Mercurial on Python 2.7.3. There was consensus that fixing compatibility for a Python version more than 7 years old is not worth it. So, instead of making Mercurial crash with an obscure exception, this patch raises the minimum Python version to 2.7.4.

fsmonitor: coerce `clock` variable to byte-string (issue6321) Callers of `fsmonitor.state.setlastclock` pass their arguments wrapped in `pycompat.sysbytes` to ensure the value is a `bytes` on Python 3. However in `fsmonitor.poststatus.__call__`, if the return value of `getlastclock()` is `None`, we use the value of `fsmonitor.poststatus._startclock` instead, which is not converted to a byte string in the same manner. This commit converts the value of `startclock` to a byte string using `pycompat.sysbytes` in the constructor for `poststatus`, to avoid the "`str` + `bytes`" error from issue 6321. Differential Revision: https://phab.mercurial-scm.org/D8573

py3: change default priority and length used for sorting hooks to be compatible with python 3 The call to `sorted(hooks.values())` can on line 213 of hooks.py can raise when using python 3. For instance, when hooks.values is `[(0, 2, b'post-commit.check-status', b''), (None, None, b'changegroup.app-hooks', <object object at 0x7f5279885590>)]`, the error is `TypeError: '<' not supported between instances of 'NoneType' and 'int'` This fix keeps the same order that was used in python 2 without relying on comparison with None. Differential Revision: https://phab.mercurial-scm.org/D8527