Eliza Weisman

I'm happy to approve a pull request to add this functionality to `tracing-subscriber`, if anyone is interested in implementing it.

> Is there a reason why we can't do this? Why consume `self` for each step in the build. Many of the builder methods change a type parameter on the...

> How do you feel about adding a `with_format` option or something like that? I'd be happy to do it. https://docs.rs/tracing-subscriber/0.2.0/tracing_subscriber/fmt/struct.SubscriberBuilder.html#method.event_format :)

I would really like to figure out a nicer story for this, especially since there is probably an 0.3 release of `tracing-subscriber` on the horizon & we will have the...

Actually...while I was writing all that up, I think I came up with a fairly simple and obvious solution. Stay tuned!

> I was under the impression that you had lifted configuration to the type level solely so that you couldn't misconfigure a `Subscriber` or something. @leshow that's definitely _part_ of...

A note on the above: this won't work with cases where you want to continue calling `SubscriberBuilder` methods on a builder, as in this case that @leshow mentioned in https://github.com/tokio-rs/tracing/issues/575#issuecomment-584155410:...

I transferred this to tokio-rs/tracing. Also, tagging @zekisherif, since it's related to the `tracing-appender` crate.

@zekisherif > 1. Changing the `RotationKind` will be a breaking change as `RollingFileAppender` is public and people may be using it directly instead of one of the helper functions. I...

> Should I open a draft PR? If you like, please do!