root:
             product   file:plan.py
             product   step:./plan.py

file:plan.py
               state = CONFIRMED
             creator   root:
                sink   step:./plan.py

step:./plan.py
               state = SUCCEEDED
                need = PLAN
           using_env = STEPUP_PATH_FILTER [dynamic]
             creator   root:
              source   file:plan.py
             product   file:args.json
             product   file:data.txt
             product   file:work.py
             product   step:./work.py run --inp=args.json
                sink   file:args.json [dynamic]

file:data.txt
               state = CONFIRMED
             creator   step:./plan.py
                sink   step:./work.py run --inp=args.json

file:work.py
               state = CONFIRMED
             creator   step:./plan.py
                sink   step:./work.py run --inp=args.json

file:args.json
               state = BUILT
             creator   step:./plan.py
              source   step:./plan.py
                sink   step:./work.py run --inp=args.json

step:./work.py run --inp=args.json
               state = SUCCEEDED
                need = DEFAULT
           using_env = STEPUP_PATH_FILTER [dynamic]
             creator   step:./plan.py
              source   file:args.json
              source   file:data.txt
              source   file:work.py
             product   file:result.txt
                sink   file:result.txt

file:result.txt
               state = BUILT
             creator   step:./work.py run --inp=args.json
              source   step:./work.py run --inp=args.json
