$ git clone -n https://src.fedoraproject.org/rpms/rubygem-memfs.git /var/lib/mock/f45-build-35082-693/root/chroot_tmpdir/scmroot/rubygem-memfs
Cloning into '/var/lib/mock/f45-build-35082-693/root/chroot_tmpdir/scmroot/rubygem-memfs'...
$ git fetch origin 193f0f510488fd007cfe6a43f16736385d150286:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rubygem-memfs
 * [new ref]         193f0f510488fd007cfe6a43f16736385d150286 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 193f0f5 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild