$ git clone -n https://src.fedoraproject.org/rpms/reproc.git /var/lib/mock/f45-build-34474-687/root/chroot_tmpdir/scmroot/reproc
Cloning into '/var/lib/mock/f45-build-34474-687/root/chroot_tmpdir/scmroot/reproc'...
$ git fetch origin 86179d5f5d0f22e6d50c9c99da4e29674933a76e:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/reproc
 * [new ref]         86179d5f5d0f22e6d50c9c99da4e29674933a76e -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 86179d5 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild