$ git clone -n https://src.fedoraproject.org/rpms/rxvt-unicode.git /var/lib/mock/f41-build-816472-150205/root/chroot_tmpdir/scmroot/rxvt-unicode
Cloning into '/var/lib/mock/f41-build-816472-150205/root/chroot_tmpdir/scmroot/rxvt-unicode'...
$ git fetch origin 6fac20a668dfa0a5d8c07d0a2f2e7c59bcfbf568:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rxvt-unicode
 * [new ref]         6fac20a668dfa0a5d8c07d0a2f2e7c59bcfbf568 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 6fac20a Perl 5.40 rebuild