$ git clone -n https://src.fedoraproject.org/rpms/perl-mixin.git /var/lib/mock/f45-build-27714-625/root/chroot_tmpdir/scmroot/perl-mixin
Cloning into '/var/lib/mock/f45-build-27714-625/root/chroot_tmpdir/scmroot/perl-mixin'...
$ git fetch origin ed6853f728018e0a83c52770db12f56cea2c53fb:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-mixin
 * [new ref]         ed6853f728018e0a83c52770db12f56cea2c53fb -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at ed6853f Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild