$ git clone -n https://src.fedoraproject.org/rpms/javapackages-bootstrap.git /var/lib/mock/f40-build-2165357-50976/root/chroot_tmpdir/scmroot/javapackages-bootstrap
Cloning into '/var/lib/mock/f40-build-2165357-50976/root/chroot_tmpdir/scmroot/javapackages-bootstrap'...
$ git fetch origin 1b9d2b5319748484bea5bc071a0a0298906b5cbb:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/javapackages-bootstrap
 * [new ref]         1b9d2b5319748484bea5bc071a0a0298906b5cbb -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 1b9d2b5 Update to upstream version 1.14.0