hghave: add a checker for the vcr HTTP record/replay library I'm going to use this to write some tests of the phabricator extension. Differential Revision: https://phab.mercurial-scm.org/D4598

py3: allow run-tests.py to run on Windows This is now functional: HGMODULEPOLICY=py py -3 run-tests.py --local test-help.t --pure --view bcompare However, on this machine without a C compiler, it tries to load cext anyway, and blows up. I haven't looked into why, other than to see that it does set the environment variable. When the test exits though, I see it can't find killdaemons.py, get-with-headers.py, etc. I have no idea why these changes are needed, given that it runs on Linux. But os.system() is insisting that it take a str, and subprocess.Popen() blows up without str: Errored test-help.t: Traceback (most recent call last): File "run-tests.py", line 810, in run self.runTest() File "run-tests.py", line 858, in runTest ret, out = self._run(env) File "run-tests.py", line 1268, in _run exitcode, output = self._runcommand(cmd, env) File "run-tests.py", line 1141, in _runcommand env=env) File "C:\Program Files\Python37\lib\subprocess.py", line 756, in __init__ restore_signals, start_new_session) File "C:\Program Files\Python37\lib\subprocess.py", line 1100, in _execute_child args = list2cmdline(args) File "C:\Program Files\Python37\lib\subprocess.py", line 511, in list2cmdline needquote = (" " in arg) or ("\t" in arg) or not arg TypeError: argument of type 'int' is not iterable This is exactly how it crashes when trying to spin up a pager too. I left one instance of os.system() unchanged in _installhg(), because it doesn't get there.

py3: ensure run-tests environment is uniformly str subprocess.popen() was crashing, and when I printed out `env`, all of the keys and most of the values were str. Except these.

py3: ensure run-tests.osenvironb is actually bytes Windows doesn't have os.environb, so it was falling back to the Unicode form, and all of the accesses are trying to use bytes.

py3: fix str vs bytes in enough places to run `hg version` on Windows I don't have Visual Studio 2015 at home, but this now works with a handful of extensions (blackbox, extdiff, patchbomb, phabricator and rebase, but not evolve): $ HGMODULEPOLICY=py py -3 ../hg version Enabling the evolve extension causes the usual "failed to import ..." line, but then print this before the usual version output: ('commit', '[b'debugancestor', b'debugapplystreamclonebundle', ..., b'verify', b'version']') ... where the elided part seems to be every command and alias known.

windows: open registry keys using unicode names Python3 complained it must be str. While here, use a context manager to close the key- it wouldn't wrap at 80 characters the old way, and would have had to move anyway.

py3: byteify strings in pycompat These surfaced when disabling the source transformer to debug the problems in win32.py. ./contrib/byteify-strings.py found a couple false positives, so I marked them with r'' explicitly (in case I'm wrong). # skip-blame since this is just b'' and r'' prefixing