$ git clone -n https://src.fedoraproject.org/rpms/perl-XML-Merge.git /var/lib/mock/f45-build-27498-624/root/chroot_tmpdir/scmroot/perl-XML-Merge
Cloning into '/var/lib/mock/f45-build-27498-624/root/chroot_tmpdir/scmroot/perl-XML-Merge'...
$ git fetch origin dab3dab29dba6c29e88b4582047fd14d447882e3:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-XML-Merge
 * [new ref]         dab3dab29dba6c29e88b4582047fd14d447882e3 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at dab3dab Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild