root:
             creates   file:./
             creates   file:plan.py
             creates   step:runpy ./plan.py

file:./
               state = STATIC
          created by   root:
            supplies   file:plan.py
            supplies   file:sub/
            supplies   step:runpy ./plan.py

file:plan.py
               state = STATIC
          created by   root:
            consumes   file:./
            supplies   step:runpy ./plan.py

step:runpy ./plan.py
               state = SUCCEEDED
             env_var = STEPUP_PATH_FILTER [amended]
          created by   root:
            consumes   file:./
            consumes   file:plan.py
             creates   file:sub/
             creates   file:sub/plan.py
             creates   step:runpy ./plan.py  # wd=sub/

file:sub/
               state = STATIC
          created by   step:runpy ./plan.py
            consumes   file:./
            supplies   file:sub/copy.txt
            supplies   file:sub/plan.py
            supplies   file:sub/used.txt
            supplies   step:copy used.txt copy.txt  # wd=sub/
            supplies   step:runpy ./plan.py  # wd=sub/

file:sub/plan.py
               state = STATIC
          created by   step:runpy ./plan.py
            consumes   file:sub/
            supplies   step:runpy ./plan.py  # wd=sub/

step:runpy ./plan.py  # wd=sub/
               state = SUCCEEDED
             env_var = STEPUP_PATH_FILTER [amended]
          created by   step:runpy ./plan.py
            consumes   file:sub/
            consumes   file:sub/plan.py
             creates   dg:sub/u*.txt
             creates   step:copy used.txt copy.txt  # wd=sub/

dg:sub/u*.txt
          created by   step:runpy ./plan.py  # wd=sub/
             creates   file:sub/used.txt

step:copy used.txt copy.txt  # wd=sub/
               state = SUCCEEDED
          created by   step:runpy ./plan.py  # wd=sub/
            consumes   file:sub/
            consumes   file:sub/used.txt
             creates   file:sub/copy.txt
            supplies   file:sub/copy.txt

file:sub/used.txt
               state = STATIC
          created by   dg:sub/u*.txt
            consumes   file:sub/
            supplies   step:copy used.txt copy.txt  # wd=sub/

file:sub/copy.txt
               state = BUILT
          created by   step:copy used.txt copy.txt  # wd=sub/
            consumes   file:sub/
            consumes   step:copy used.txt copy.txt  # wd=sub/
