$ git clone -n https://src.fedoraproject.org/rpms/perl-Mixin-Linewise.git /var/lib/mock/f45-build-24817-606/root/chroot_tmpdir/scmroot/perl-Mixin-Linewise
Cloning into '/var/lib/mock/f45-build-24817-606/root/chroot_tmpdir/scmroot/perl-Mixin-Linewise'...
$ git fetch origin f4f8ce6cdca25fad9955b338c2009cc13a69b4da:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-Mixin-Linewise
 * [new ref]         f4f8ce6cdca25fad9955b338c2009cc13a69b4da -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at f4f8ce6 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild