In reply to @pmunch "What do you mean?": Tools such as `expect`, or libraries
such as Python's `pexpect`,  and taken 1 step further testing framework for
defining unit tests that could leverage a module/library similar to `pexpect`,
but which handled defining unsolicited error output such as a segfault.
(catching unsolicited outputs can be done in `pexpect`, but it requires
developing a custom framework around it).

Also, the ability to pass custom file descriptors to said tooling in order to
handle said unit tests which may need to be via some sort of proxy execution
handler (ttySN, qemu, ssh, etc).