$ git clone -n https://src.fedoraproject.org/rpms/maven-mapping.git /var/lib/mock/f40-build-2243786-53698/root/chroot_tmpdir/scmroot/maven-mapping
Cloning into '/var/lib/mock/f40-build-2243786-53698/root/chroot_tmpdir/scmroot/maven-mapping'...
$ git fetch origin 5b9e91efd9b7397e266b647b019e9735dda59e2e:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/maven-mapping
 * [new ref]         5b9e91efd9b7397e266b647b019e9735dda59e2e -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 5b9e91e Update javapackages test plan to f40