In tests, what do others think about adding dbg!. Idea being provided additional info when tests fail.

[Ben-PH]

e.g. add to a code style guide something like this:

When writing tests, consider how a test might fail, and add dbg! statements where they would be of particular use. consider the following:

• The value of self-documentation. When an error occurs, the dbg! should indicate a section of the test that should be considered more carefully in the failure
• Performance. dbg! might be expensive when the cached output becomes very large.

The context I was working in that gave me the idea to raise this discussion can be found in #3846 . Having the dbg! might have made understanding the source of the problems easier to grasp.

[AurelienFT]

We don't have a coding style guide for now we only match clippy and rustfmt maybe we could add one and this could be one of the rules but it's a more bigger project.