$ git clone -n https://src.fedoraproject.org/rpms/perl-Proc-Fork.git /var/lib/mock/f45-build-25930-613/root/chroot_tmpdir/scmroot/perl-Proc-Fork
Cloning into '/var/lib/mock/f45-build-25930-613/root/chroot_tmpdir/scmroot/perl-Proc-Fork'...
$ git fetch origin 3eec53ae8ba5842609bda8208a6cbaaea3f7a1da:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-Proc-Fork
 * [new ref]         3eec53ae8ba5842609bda8208a6cbaaea3f7a1da -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 3eec53a Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild