$ git clone -n https://src.fedoraproject.org/rpms/rubygem-gio2.git /var/lib/mock/f43-build-side-115085-61058626-6588310/root/chroot_tmpdir/scmroot/rubygem-gio2
Cloning into '/var/lib/mock/f43-build-side-115085-61058626-6588310/root/chroot_tmpdir/scmroot/rubygem-gio2'...
$ git fetch origin e0ca20adb8aca37944fe18e9be3e3d11496b5cba:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rubygem-gio2
 * [new ref]         e0ca20adb8aca37944fe18e9be3e3d11496b5cba -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at e0ca20a 4.3.0 entry