$ git clone -n https://src.fedoraproject.org/rpms/perl-DateTime-Calendar-Mayan.git /var/lib/mock/f45-build-22950-595/root/chroot_tmpdir/scmroot/perl-DateTime-Calendar-Mayan
Cloning into '/var/lib/mock/f45-build-22950-595/root/chroot_tmpdir/scmroot/perl-DateTime-Calendar-Mayan'...
$ git fetch origin 2d15fcbe46bfd11b66a121f14177a9f1186097f2:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-DateTime-Calendar-Mayan
 * [new ref]         2d15fcbe46bfd11b66a121f14177a9f1186097f2 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 2d15fcb Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild