Support dash in target names

[bkchr]

This adds support for having dashes in log target names, like:
target-name=info

Motivation

We are using log targets with dashes in our project.

Solution

Extend the target parsing regex to support dashes.

[hawkw]

This looks good to me!

It might be worth adding a note to the docs that when a crate's name has a dash in it, the default target for events in that crate will be the crate's module path as it appears in Rust code, so the dash will be turned into an underscore. Dashes will only appear in targets when you write an explicit target string like

tracing::info!(target: "target-name", ...);

[davidbarsky]

This seems like a reasonable change, but does rust-lang/log support hyphens in their target names?

I would assume that targets follow legal Rust syntax and I don't believe hyphens are.

[bkchr]

This seems like a reasonable change, but does rust-lang/log support hyphens in their target names?

I would assume that targets follow legal Rust syntax and I don't believe hyphens are.

We used before env_logger and that supported dashes.

[bkchr]

This looks good to me!

It might be worth adding a note to the docs that when a crate's name has a dash in it, the default target for events in that crate will be the crate's module path as it appears in Rust code, so the dash will be turned into an underscore. Dashes will only appear in targets when you write an explicit target string like

tracing::info!(target: "target-name", ...);

Can you give me a pointer where I should add this?

[bkchr]

And any idea why macos is failing? Is this a known error?

[hawkw]

And any idea why macos is failing? Is this a known error?

That test fails spuriously sometimes...I really need to fix that. I went ahead and restarted CI for you.

This looks good to me!
It might be worth adding a note to the docs that when a crate's name has a dash in it, the default target for events in that crate will be the crate's module path as it appears in Rust code, so the dash will be turned into an underscore. Dashes will only appear in targets when you write an explicit target string like

tracing::info!(target: "target-name", ...);

Can you give me a pointer where I should add this?

Maybe in the "Usage Notes" section?

[bkchr]

@hawkw done

[bkchr]

And @hawkw would it be possible to release this afterwards relative shortly?

[hawkw]

And @hawkw would it be possible to release this afterwards relative shortly?

If you need to get this published soon, you'll need to open another PR to merge this into the v0.1.x branch as well. The master branch currently contains breaking changes for the upcoming tracing 0.2 release (which should be out in a couple of weeks); in order to release these changes immediately they need to be backported to the current version.

Since I've already approved this PR, though, I'll happily merge the same changes into v0.1.x!