pycompat: change users of pycompat.{stdin,stdout,stderr} to use procutil.std* On Python 3, pycompat.{stdin,stdout,stderr} are usually block-buffered even if connected to a TTY. procutil.{stdin,stdout,stderr} provide consistent behavior across platforms and Python versions.

hgignore: add mypy cache files Differential Revision: https://phab.mercurial-scm.org/D8692

revlog: avoid hard-coded hash sizes Differential Revision: https://phab.mercurial-scm.org/D8683

test: restore expected output in test-persistent-nodemap.t The merge 78cafd48b9b2 had a small error and wrongly dropped the output updated from one side of the merge. This changeset re-install it. Differential Revision: https://phab.mercurial-scm.org/D8678

heptapod-ci: build rhg before tests run Differential Revision: https://phab.mercurial-scm.org/D8682

rhg: add a limited `rhg root` subcommand Clap has been choosen for argument parsing for the following reasons: - it's a wildly used and maintained crate - it can deal with OS encoding making it suitable for any encoding - it supports nonambiguous prefix matching as already available in hg - it will soon allow for structopts-style declarative pattern instead of the currently used builder pattern Differential Revision: https://phab.mercurial-scm.org/D8613

rhg: add RootCommand using hg-core FindRoot operation to prepare `hg root` The println macro is not used to avoid string usage. Dealing only with bytes allows us to be compatible with any encoding and not just UTF8. Later on, format macro will be made to have more readable code. Differential Revision: https://phab.mercurial-scm.org/D8612

archival: abort if compression method is unavailable `tarfile.CompressionError` is documented to be the "exception for unavailable compression methods". Also, make tests conditional on whether the lzma module is available or not.

demandimport: ignore `lzma` module for demandimport This makes importing the module fail if the `_lzma` module is not present. This makes e.g. tarfile correctly recognize if LZMA support is not present. It changes the exception File "/usr/lib/python3.6/tarfile.py", line 1694, in xzopen fileobj = lzma.LZMAFile(fileobj or name, mode, preset=preset) AttributeError: module 'lzma' has no attribute 'LZMAFile' to the more correct exception File "/usr/lib/python3.6/tarfile.py", line 1692, in xzopen raise CompressionError("lzma module is not available") tarfile.CompressionError: lzma module is not available Also, it prevents that the error "abort: No module named '_lzma'!" is shown when a development warning is to be shown. The reason why that happened is that for showing the warning, we get information about the stack frames from the inspect module, which accesses the `__file__` attribute of all modules in `sys.modules` to build some cache, causing all modules (including `lzma`) to be imported.

merge with stable