$ git clone -n https://src.fedoraproject.org/rpms/perl-Devel-Size.git /var/lib/mock/f45-build-23136-596/root/chroot_tmpdir/scmroot/perl-Devel-Size
Cloning into '/var/lib/mock/f45-build-23136-596/root/chroot_tmpdir/scmroot/perl-Devel-Size'...
$ git fetch origin 2ba569d7782c0b05dd3ec32c374cf9533ee26158:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-Devel-Size
 * [new ref]         2ba569d7782c0b05dd3ec32c374cf9533ee26158 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 2ba569d Perl 5.44 rebuild