$ git clone -n https://src.fedoraproject.org/rpms/perl-Math-Base-Convert.git /var/lib/mock/f45-build-24668-605/root/chroot_tmpdir/scmroot/perl-Math-Base-Convert
Cloning into '/var/lib/mock/f45-build-24668-605/root/chroot_tmpdir/scmroot/perl-Math-Base-Convert'...
$ git fetch origin 3d6e2b4aa94153ed6d8618610bcbc76d6e60089d:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-Math-Base-Convert
 * [new ref]         3d6e2b4aa94153ed6d8618610bcbc76d6e60089d -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 3d6e2b4 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild