$ git clone -n https://src.fedoraproject.org/rpms/perl-Math-Calc-Units.git /var/lib/mock/f45-build-24675-605/root/chroot_tmpdir/scmroot/perl-Math-Calc-Units
Cloning into '/var/lib/mock/f45-build-24675-605/root/chroot_tmpdir/scmroot/perl-Math-Calc-Units'...
$ git fetch origin 2206170accf3837e440e8e9083709b3aa5739d83:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-Math-Calc-Units
 * [new ref]         2206170accf3837e440e8e9083709b3aa5739d83 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 2206170 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild