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 = ENV_VAR_TEST_STEPUP_PREFIX [dynamic]
                     = STEPUP_PATH_FILTER [dynamic]
           explained = yes
             creator   root:
              source   file:plan.py
             product   file:README.txt
             product   step:grep variable README.txt ${ENV_VAR_TEST_STEPUP_PREFIX}.txt > README-stdout.txt 2> README-stderr.txt

file:README.txt
               state = CONFIRMED
             creator   step:./plan.py
                sink   step:grep variable README.txt ${ENV_VAR_TEST_STEPUP_PREFIX}.txt > README-stdout.txt 2> README-stderr.txt

step:grep variable README.txt ${ENV_VAR_TEST_STEPUP_PREFIX}.txt > README-stdout.txt 2> README-stderr.txt
               state = SUCCEEDED
                need = DEFAULT
           using_env = ENV_VAR_TEST_STEPUP_PREFIX
           explained = yes
             creator   step:./plan.py
              source   file:README.txt
             product   file:README-stderr.txt
             product   file:README-stdout.txt
                sink   file:README-stderr.txt
                sink   file:README-stdout.txt

file:README-stdout.txt
               state = BUILT
             creator   step:grep variable README.txt ${ENV_VAR_TEST_STEPUP_PREFIX}.txt > README-stdout.txt 2> README-stderr.txt
              source   step:grep variable README.txt ${ENV_VAR_TEST_STEPUP_PREFIX}.txt > README-stdout.txt 2> README-stderr.txt

file:README-stderr.txt
               state = VOLATILE
             creator   step:grep variable README.txt ${ENV_VAR_TEST_STEPUP_PREFIX}.txt > README-stdout.txt 2> README-stderr.txt
              source   step:grep variable README.txt ${ENV_VAR_TEST_STEPUP_PREFIX}.txt > README-stdout.txt 2> README-stderr.txt
