When "-n" is generated by the property tests, it causes `echo` to not
output the string since it's interpreted as an option. Apparently
there's no good way to print "-n" with `echo` [1], so switching to
`printf` instead
[1]: https://unix.stackexchange.com/questions/85846/how-can-i-print-n-with-echo
Adds initial work towards a `lib.path` library
Originally proposed in https://github.com/NixOS/nixpkgs/pull/200718, but has
since gone through some revisions
Co-Authored-By: Valentin Gagarin <valentin.gagarin@tweag.io>
Co-Authored-By: Robert Hensing <robert@roberthensing.nl>
