Solves 1/3 of the infinite recursion at unknown location meme.
See #8879 for ensuring we always have a trace (for stack overflows)
We might want to re-add this for finding missing location info
*while hacking on that problem only*.
* Lang now verifies errors and parse output
* Some new miscellaneous tests
* Easy way to update the tests
* Document workflow in manual
* Use `!` not `~` as separater char for sed
It is confusing to use `~` when we are talking about paths and home
directories!
* Test test suite itself (`test/lang-test/infra.sh`)
Additionally, run shellcheck on `tests/lang.sh` to help ensure it is
correct, now that is is more complex.
Co-authored-by: Robert Hensing <roberth@users.noreply.github.com>
Co-authored-by: Valentin Gagarin <valentin.gagarin@tweag.io>