$ git clone -n https://src.fedoraproject.org/rpms/xdelta.git /var/lib/mock/f41-build-755449-13413/root/chroot_tmpdir/scmroot/xdelta
Cloning into '/var/lib/mock/f41-build-755449-13413/root/chroot_tmpdir/scmroot/xdelta'...
$ git fetch origin 081419eff05c5da868e9aca99367298f0efe5b0a:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/xdelta
 * [new ref]         081419eff05c5da868e9aca99367298f0efe5b0a -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 081419e Eliminate use of obsolete %patchN syntax (#2283636)