Fix build error in egui-winit with profiling enabled

[torokati44]

Fixes #7555.

Verified by patching ruffle to use a checked out egui repo with this change, and running cargo run --release --features=tracy in it.

I hesitated between & and .as_str() - if you'd prefer the latter, let me know.

[github-actions]

Preview available at https://egui-pr-preview.github.io/pr/7557-fix-profiling-build-error
Note that it might take a couple seconds for the update to show up after the preview_build workflow has completed.

[emilk]

We should make sure this is caught by CI 🤔

[emilk]

I fail to reproduce the problem locally - what command are you running to get a build error?

[torokati44]

For example, cargo clippy --workspace --all-features in ruffle-rs/ruffle#21730.

[torokati44]

The point is to get the profiling/profile-with-tracy feature enabled (possibly an issue with other profile-with-... features too, haven't checked).

[emilk]

But the problem doesn't repo in the egui repository? Maybe we just need to update the profiling or puffin crates?

[torokati44]

Maybe we just need to update the profiling or puffin crates?

format! returns a String: https://doc.rust-lang.org/std/macro.format.html
profiling::function_scope! takes a &str: https://docs.rs/profiling/latest/profiling/macro.function_scope.html

An example at the latter link conincidentally even has a format! in it, and it does have to have .as_str() after it...
What else could I say?

[torokati44]

It just happens to work with puffin because the profiling impl for it expands to a function call that is more lax, taking impl AsRef<str>:
https://github.com/aclysma/profiling/blob/740d74c82212f1f0584cfa5c6d884c5ab5367101/profiling/src/puffin_impl.rs#L17
https://docs.rs/puffin/0.19.1/src/puffin/lib.rs.html#252-275
https://docs.rs/puffin/0.19.1/puffin/struct.ProfilerScope.html#method.new
Arguably, it shouldn't.

While for the tracy backend, it is &str all the way through macro expansion:
https://github.com/aclysma/profiling/blob/740d74c82212f1f0584cfa5c6d884c5ab5367101/profiling/src/tracy_impl.rs#L48
https://docs.rs/tracy-client/0.18.2/tracy_client/struct.Span.html#method.emit_text

[torokati44]

But the problem doesn't repo in the egui repository?

Something would have to enable the profiling/profile-with-tracy feature, but nothing does, plus, it seems like it is mutually exclusive with profiling/profile-with-puffin (and probably all the others too), so...

[emilk]

I see - thanks for explaining it