$ git clone -n https://src.fedoraproject.org/rpms/deja-dup.git /var/lib/mock/f39-build-1701747-41210/root/chroot_tmpdir/scmroot/deja-dup
Cloning into '/var/lib/mock/f39-build-1701747-41210/root/chroot_tmpdir/scmroot/deja-dup'...
$ git fetch origin fc15cd635db2edbafdd001c9d4a4bc6600e083b1:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/deja-dup
 * [new ref]         fc15cd635db2edbafdd001c9d4a4bc6600e083b1 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at fc15cd6 45.1