If a test need to clean up itself disregarding test status,
it can add an optional test-cleanup phase.
This is useful if the test in some circomstances leave the device in a
bad state. This can be used to restore the unit to its ordinary state.
Avoid having log messages stuck in a pipe when stdout is not a tty,
e.g. when running a suite of tests using 9pm.
Two benefits:
- Nicer experience when interactively running a suite
- Timestamps inserted by 9pm are more useful
It is not uncommon for subprocesses to fail when developing new tests,
but the default representation of CalledProcessError does not print
the stdout of the program, only that it failed.
Catch this common case when a test is about to fail, and make sure to
log any output it produced.
Mattias Walström