$ git clone -n https://src.fedoraproject.org/rpms/perl-Text-JSCalendar.git /var/lib/mock/f45-build-27015-620/root/chroot_tmpdir/scmroot/perl-Text-JSCalendar
Cloning into '/var/lib/mock/f45-build-27015-620/root/chroot_tmpdir/scmroot/perl-Text-JSCalendar'...
$ git fetch origin bd66fd4962c3cac4aeaae91b97050d262a53ba34:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-Text-JSCalendar
 * [new ref]         bd66fd4962c3cac4aeaae91b97050d262a53ba34 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at bd66fd4 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild