largefiles: make sure debugstate command is populated before wrapping Copied the hack from 869d660b8669, which seemed the simplest workaround. Perhaps debugcommands.py should have its own commands table.

check-code: ignore re-exports of os.environ in encoding.py These are valid uses of os.environ.

check-code: exclude demandimport.py and policy.py from Python 3 checks These modules can't depend on pycompat.py, which means we have to write Py3 hacks in them.

check-code: rewrite py3 exclusion pattern with negative lookahead I want to add more patterns, but negative lookbehind requires patterns of the same length so not useful.

cleanup: remove useless re-raises of KeyboardInterrupt KeyboardInterrupt is no longer a subclass of Exception since Python 2.5. https://docs.python.org/2/whatsnew/2.5.html#pep-352-exceptions-as-new-style-classes

make: drop deprecated rule to process temporary copy of pure modules Pure modules never be copied to mercurial/ since 511a4384b033.

help: describe about choice of :prompt as a fallback merge tool explicitly "merge-tools" help topic has described that the merge of the file fails if no tool is found to merge binary or symlink, since c77f6276c9e7 (or Mercurial 1.7), which based on (already removed) MergeProgram wiki page. But even at that revision, and of course now, merge of the file doesn't fail automatically for binary/symlink. ":prompt" (or equivalent logic) is used, if there is no appropriate tool configuration for binary/symlink.