usage: tautline red-green-check [-h] [--target TARGET] --file FILE
                                --test-command TEST_COMMAND
                                [--timeout TIMEOUT]

options:
  -h, --help            show this help message and exit
  --target TARGET       Working directory the test command runs in.
  --file FILE           Source file to mutate.
  --test-command TEST_COMMAND
                        Command (run via bash -c in --target) that should FAIL
                        when the code breaks.
  --timeout TIMEOUT     Seconds allowed per test-command run (baseline and
                        each mutation), default 600. A run that hits this
                        reports inconclusive(timeout) rather than hanging.
