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:../../common/script.py
             product   step:./script.py  # wd=../../common

file:../../common/script.py
               state = CONFIRMED
             creator   step:./plan.py
                sink   step:./script.py  # wd=../../common

step:./script.py  # wd=../../common
               state = SUCCEEDED
                need = DEFAULT
           using_env = STEPUP_PATH_FILTER [dynamic]
             creator   step:./plan.py
              source   file:../../common/script.py
             product   file:../public/foo.txt
                sink   file:../public/foo.txt [dynamic]

file:../public/foo.txt
               state = BUILT
             creator   step:./script.py  # wd=../../common
              source   step:./script.py  # wd=../../common
