[Feature discussion] I clarified an error message, but the CONTRIBUTING guide says to discuss it first

[Doshirae]

Hello, as the title says, I modified a bit the code to clarify an error message, but before actually doing a PR, I saw that the feature had to be discussed in the issue tracker. I didn't make any tests yet, because I don't know how to proceed to do that, that is actually my first contribution ever…

Any help is welcome

[jelmer]

What's the error message, and what are you proposing it be changed to?