$ git clone -n https://src.fedoraproject.org/rpms/perl-CPAN-Changes.git /var/lib/mock/f45-build-21965-589/root/chroot_tmpdir/scmroot/perl-CPAN-Changes
Cloning into '/var/lib/mock/f45-build-21965-589/root/chroot_tmpdir/scmroot/perl-CPAN-Changes'...
$ git fetch origin 905c4cec6570d51560a0b3cea75b6697ff7304f3:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-CPAN-Changes
 * [new ref]         905c4cec6570d51560a0b3cea75b6697ff7304f3 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 905c4ce Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild