$ git clone -n https://src.fedoraproject.org/rpms/bign-handheld-thumbnailer.git /var/lib/mock/f43-build-61064868-6588446/root/chroot_tmpdir/scmroot/bign-handheld-thumbnailer
Cloning into '/var/lib/mock/f43-build-61064868-6588446/root/chroot_tmpdir/scmroot/bign-handheld-thumbnailer'...
$ git fetch origin 48f73584b9c01ebba4d1e074841879987fff9ffe:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/bign-handheld-thumbnailer
 * [new ref]         48f73584b9c01ebba4d1e074841879987fff9ffe -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 48f7358 Update to 1.1.3