$ git clone -n https://src.fedoraproject.org/rpms/rust-gstreamer-player.git /var/lib/mock/f39-build-2261262-54414/root/chroot_tmpdir/scmroot/rust-gstreamer-player
Cloning into '/var/lib/mock/f39-build-2261262-54414/root/chroot_tmpdir/scmroot/rust-gstreamer-player'...
$ git fetch origin b2d016deccf3e72978ce03d8e5e67d7539275643:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-gstreamer-player
 * [new ref]         b2d016deccf3e72978ce03d8e5e67d7539275643 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b2d016d Update to version 0.21.2; Fixes RHBZ#2249240