$ git clone -n https://src.fedoraproject.org/rpms/rust-gstreamer-base.git /var/lib/mock/f40-build-2701888-70523/root/chroot_tmpdir/scmroot/rust-gstreamer-base
Cloning into '/var/lib/mock/f40-build-2701888-70523/root/chroot_tmpdir/scmroot/rust-gstreamer-base'...
$ git fetch origin 8488b1f0cae7895967a85b5ab37c09f5d2fdc1db:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-gstreamer-base
 * [new ref]         8488b1f0cae7895967a85b5ab37c09f5d2fdc1db -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 8488b1f Update to version 0.22.0; Fixes RHBZ#2263352