chg: set CHGHG before connecting to command server
cf4d2f31 (!523) changed chg to set `CHGHG` itself when spawning a new command
server, in order to ensure that the path to the `hg` executable would be checked
during server validation. (This is useful when chg is built with `HGPATHREL`).
However, that change broke chg because it failed to set `CHGHG` before trying
to connect to an existing command server. This means that if `CHGHG` is not
present in the environment, chg will always spawn a new command server, entirely
negating the point of chg.
This breakage wasn't initially caught because of the difficulty of writing
automated tests with the `HGPATHREL` feature enabled, which meant the change
was only tested manually to make sure that it fixed the problem with `HGPATHREL`
that prompted the change.
In practice, this functionality is only really useful when chg is built with
`HGPATHREL`, so I considered wrapping it in an `#ifdef` to preserve the old
behavior by default. However, this makes it hard to write tests since one would
have to explicitly set `HGPATHREL=1` when running `run-tests.py` (which is why
the original change lacked tests). It would be great if there were a way of
testing features that are gated behind conditional compilation.
Mercurial
=========
Mercurial is a fast, easy to use, distributed revision control tool
for software developers.
Basic install::
$ make # see install targets
$ make install # do a system-wide install
$ hg debuginstall # sanity-check setup
$ hg # see help
Running without installing::
$ make local # build for inplace usage
$ ./hg --version # should show the latest version
See https://mercurial-scm.org/ for detailed installation
instructions, platform-specific notes, and Mercurial user information.
Notes for packagers
===================
Mercurial ships a copy of the python-zstandard sources. This is used to
provide support for zstd compression and decompression functionality. The
module is not intended to be replaced by the plain python-zstandard nor
is it intended to use a system zstd library. Patches can result in hard
to diagnose errors and are explicitly discouraged as unsupported
configuration.