Would nicer error messages be possible?

[torpak]

When i didn't provide a valid boolean, i got a not so nice error message:

thor bla aged
thread 'main' panicked at 'Failed to parse value. Double check!: ParseBoolError { _priv: () }', libcore/result.rs:945:5
note: Run with `RUST_BACKTRACE=1` for a backtrace.

Would it be possible to instead print something like:
Error: <drunk> needs to be "true" or "false"
or something similar?

[spacekookie]

This would be really nice 👍 I'll look into doing this in a way that is nicely expandable in the future as well.