feat: allow using specific formatters for tracing

[ctron]

No description provided.

[d-e-s-o]

Thanks for the PR. It fails to build with cargo check --tests --no-default-features --features=trace. Please also revert spurious formatting changes.

In general I am not yet sold on us wanting such a change. There are more configurations available and there could be a case made for configurability of all of them -- and such support will add complexity with very little use. At the end of the day, who cares what format is being used for a given test. If it was for programmatic evaluation using JSON, perhaps there would be a stronger case. But again we run into similar problems to the above where an additional feature is required and it is rather cumbersome to enable that.

[ctron]

Sure, let me take a look and fix those issues.

who cares what format is being used for a given test.

I do, the default format of tracing feels quite unreadable. Using "pretty" at least gives some simple lines, allow to grep away the nested stuff.

[ctron]

Please also revert spurious formatting changes.

They seem to come from running cargo fmt. That isn't to be used?

[ctron]

Fixed the issue with cargo check --tests --no-default-features --features=trace.

Also reverted the changes from cargo fmt.

[ctron]

Fixed the issue with cargo check --tests --no-default-features --features=trace.

That change only fixed it for the command line. Not for a dependency. I'll need to take another look.

[ctron]

Fixed the issue with cargo check --tests --no-default-features --features=trace.

That change only fixed it for the command line. Not for a dependency. I'll need to take another look.

Looks good now.

[d-e-s-o]

Thanks for the feature proposal. After some back and forth, I have decided to pass on this functionality: the complexity of the additional conditional compilation seems too high for such a niche feature (nobody has asked for it thus far) and there is no clear line to be drawn between these fixed formats and a fully blown language of sorts for making everything that tracing-subscriber allows to configure configurable through env variables.