$ git clone -n https://src.fedoraproject.org/rpms/srt.git /var/lib/mock/f41-build-side-1-3136278-39771/root/chroot_tmpdir/scmroot/srt
Cloning into '/var/lib/mock/f41-build-side-1-3136278-39771/root/chroot_tmpdir/scmroot/srt'...
$ git fetch origin c6b8e70480107c209afb166685bfae62572e1d79:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/srt
 * [new ref]         c6b8e70480107c209afb166685bfae62572e1d79 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at c6b8e70 Update to 1.5.4