$ git clone -n https://src.fedoraproject.org/rpms/libguestfs.git /var/lib/mock/f43-perl-60958737-6586769/root/chroot_tmpdir/scmroot/libguestfs
Cloning into '/var/lib/mock/f43-perl-60958737-6586769/root/chroot_tmpdir/scmroot/libguestfs'...
$ git fetch origin 712bdd9c94ffef40da1152a78138584835cb1fcf:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/libguestfs
 * [new ref]         712bdd9c94ffef40da1152a78138584835cb1fcf -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 712bdd9 Perl 5.42 rebuild