$ git clone -n https://src.fedoraproject.org/rpms/rust-gstreamer-base.git /var/lib/mock/f40-build-2258534-54349/root/chroot_tmpdir/scmroot/rust-gstreamer-base
Cloning into '/var/lib/mock/f40-build-2258534-54349/root/chroot_tmpdir/scmroot/rust-gstreamer-base'...
$ git fetch origin c74aa03998a4be9e963ceeb9252da2a97cf2eccf:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-gstreamer-base
 * [new ref]         c74aa03998a4be9e963ceeb9252da2a97cf2eccf -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at c74aa03 Update to version 0.21.2; Fixes RHBZ#2249233