README.rst

cext: use sys.executable instead of deprecated Py_GetProgramFullPath

Fix warning with Python 3.13:

    mercurial/cext/parsers.c: In function 'check_python_version':
    mercurial/cext/parsers.c:1243:30: warning: 'Py_GetProgramFullPath' is deprecated [-Wdeprecated-declarations]
     1243 |                              Py_GetProgramFullPath());
          |                              ^~~~~~~~~~~~~~~~~~~~~
    In file included from /usr/include/python3.13/Python.h:119,
                     from mercurial/cext/parsers.c:11:
    /usr/include/python3.13/pylifecycle.h:43:43: note: declared here
       43 | Py_DEPRECATED(3.13) PyAPI_FUNC(wchar_t *) Py_GetProgramFullPath(void);
          |                                           ^~~~~~~~~~~~~~~~~~~~~

At this point in time, the PyConfig struct memory has been released and the PyConfig API can't be used.

https://docs.python.org/3.13/c-api/init.html#c.Py_GetProgramFullPath recommands
using sys.executable instead. Let's assume that will work in all versions.

It would perhaps be better to use PySys_GetObject, but I prefer to stay
consistent with how the same function is retrieving sys.hexversion.

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.