This is the Git project's copy of the GNU awk (Gawk) regex
engine. It's used when Git is build with e.g. NO_REGEX=NeedsStartEnd,
or when the C library's regular expression functions are otherwise
deficient.

This is not a fork, but a source code copy. Upstream is the Gawk
project, and the sources should be periodically updated from their
copy, which can be done with:

    for f in $(find . -name '*.[ch]' -printf "%f\n"); do wget http://git.savannah.gnu.org/cgit/gawk.git/plain/support/$f -O $f; done

For ease of maintenance, and to intentionally make it inconvenient to
diverge from upstream (since it makes it harder to re-merge) any local
changes should be stored in the patches/ directory, which after doing
the above can be applied as:

    for p in patches/*; do patch -p3 < $p; done

For any changes that aren't specific to the git.git copy please submit
a patch to the Gawk project and/or to the GNU C library (the Gawk
regex engine is a periodically & forked copy from glibc.git).