meson: wire up generation of distribution archive
Meson knows to generate distribution archives via `meson dist`. In addition to generating the archive itself, this target also knows to compile and execute tests from that archive, which helps to ensure that the result is an adequate drop-in replacement for the versioned project. While this already works as-is, one omission is that we don't propagate the commit that this is built from into the resulting archive. This can be fixed though by adding a distribution script that propagates the version into the "version" file, which GIT-VERSION-GEN knows to read if present. Use GIT-VERSION-GEN to populate that file. As the script is executed in the build directory, not in the directory where we generate the archive, we have to use a shell to resolve the "MESON_DIST_ROOT" environment variable. Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>