$ git clone -n https://src.fedoraproject.org/rpms/rust-gstreamer-base /var/lib/mock/f42-build-3429013-45391/root/chroot_tmpdir/scmroot/rust-gstreamer-base
Cloning into '/var/lib/mock/f42-build-3429013-45391/root/chroot_tmpdir/scmroot/rust-gstreamer-base'...
$ git fetch origin 43cbadfa0766c6bc2fb402946498565a3cf38f1f:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-gstreamer-base
 * [new ref]         43cbadfa0766c6bc2fb402946498565a3cf38f1f -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 43cbadf Update to version 0.23.5; Fixes RHBZ#2333665