We install the rust toolchain, but then we have to manually
source it in CI since the headless containers skip over
the shell profiles that rustup typically uses.
Ideally we'd set these as variables in the main image, but
we don't have access to the buildah instance used in
ci-templates/cbuild.
However adding them to the toolbox image is good enough to
have the toolbox setup work ootb even if it doesn't call the
ci/scripts/source_image_env.sh script like the gitlab-ci jobs
will do.
Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/7816>
* Move the exported PATH variables into a script so
we can source it in all the wrapper scripts.
* Add a guard to only copy over the cache when the
SUBPROJECTS_CACHE_DIR variable is set, which only
happens on CI by default
* Make it possible to run the scripts with default
values for some of the variables, like WERROR and MESON_ARGS.
Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/7591>
The gstreamer-rs repos use debian based images already,
which we can later base on this one. Additionally it's
good to have another distro target so we avoid weird
fedoraisms when possible.
It will also be simpler to keep it up to date, as we
don't need to run the test suite against this build as
well.
Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/6656>
