[scheduling]
    [[graph]]
        R1 = a:start => b
[runtime]
    [[a]]
        script = """
while ! grep -qF 'CYLC_JOB_EXIT' "${CYLC_WORKFLOW_RUN_DIR}/log/job/1/b/NN/job.status"
do
    sleep 1
done
"""
    [[b]]
        script = cylc poll "$CYLC_WORKFLOW_ID//1/a"
