Fail CI on failed fmt or other linting file changes

[LesnyRumcajs]

Summary of changes
Changes introduced in this pull request:

• Changes the CI lint step to check for changes resulted from e.g. cargo fmt. Before they were silently discarded.

[CLAassistant]

All committers have signed the CLA.

[lemmih]

Just change the lint target to run cargo fmt --all -- --check. It should not actually do any formatting.

[LesnyRumcajs]

Just change the lint target to run cargo fmt --all -- --check. It should not actually do any formatting.

Yes, but then anyone wanting to run the lint will have to cargo fmt --all himself - trying not to introduce breaking changes to existing contributors 😄 . Plus, any further add-ons to lint that are mutating the code will get caught for free. What do you think?

[lemmih]

Just change the lint target to run cargo fmt --all -- --check. It should not actually do any formatting.

Yes, but then anyone wanting to run the lint will have to cargo fmt --all himself - trying not to introduce breaking changes to existing contributors smile . What do you think?

I think it is a mistake that lint modified the code in the first place. In my mind, linting should check for problems, not automatically fix them.

[LesnyRumcajs]

Just change the lint target to run cargo fmt --all -- --check. It should not actually do any formatting.

Yes, but then anyone wanting to run the lint will have to cargo fmt --all himself - trying not to introduce breaking changes to existing contributors smile . What do you think?

I think it is a mistake that lint modified the code in the first place. In my mind, linting should check for problems, not automatically fix them.

Indeed, I was a bit surprised myself. All right, I'll do the --check, thanks for the insight.

[lemmih]

Hopefully #1420 will soon be merged such that the audit step passes.