David Barsky

Thanks for opening this issue and sorry for taking a second to respond. `tracing` requires metadata fields like be `'static` In order to enable fast filtering of events/spans. `log` doesn't...

i'm working on backporting that feature.

I'm trying to remember if we _can_ add `Clone` to the derive list, but I recall that adding Layer implementations for `Arc` broke per-layer filtering. I don't recall if this...

> This makes sense. However, keep in mind that this log will likely be read by people that didn't write the code that emits the trace, and thus they are...

> Sounds reasonable to me, assuming that we are not close to reaching too-many-options-syndrome. I worry about that as well, but I think we'll burn that bridge once we cross...

The reproduction in #16516 seems to be substantially smaller than other examples I've seen: ```rust fn my_example( _x: impl IntoIterator, _y: impl IntoIterator, ) { let mut cmd = std::process::Command::new("foo");...

> @davidbarsky That's the same as #10653 which I'm not so sure is the same as this issue, since there are no trait bounds on type parameters in the original...

A talk at last week's Strangeloop titled ["Performance Matters"](https://www.youtube.com/watch?v=r-TLSBdHe1A) covered [coz-profiler](https://github.com/plasma-umass/coz) that's kinda magical—it finds and predicts what sort of optimizations would be useful, and how much of a throughput/latency...

@bjorn3: oh, that's a bummer, but that's good to know. I'm guessing that requires changing coz to support parking-lot's mutexes?

Sorry for the delay. I agree that we should provide customization, but my preference is to expose this through `tracing_subscriber::fmt::time::FormatTime` interface, which will function as a superset of `time::formatting::Formattable`. (We...