Nightly target-specific feature selection not supported

[dae]

Hi there,

Is my understanding correct that currently the only way to select specific features from a crate is to manually edit the generated remote/.BUILD.bazel file, removing the unwanted features from the list? I currently am using a Cargo.toml file that specifies different features for different platforms, and am wondering whether such a thing can be accomplished with Bazel now that #212 has landed.

[UebelAndre]

Hey, does the additional_flags field help you here?
https://github.com/google/cargo-raze/blob/master/examples/remote/complicated_cargo_library/Cargo.toml#L23-L26

I struggle to find a way to specify only specify a feature for a specific platform with just --cfg flags though. Maybe this is a lack of functionality on raze? Can you elaborate more on what you're trying to do and potentially provide some example? 😄 🙏

Also, There should be no reason to hand edit generated files. Definitely interested in cases where you feel that's necessary.

[UebelAndre]

Maybe rust-lang/cargo#1197 would also be relevant here?

[dae]

Sorry for the noise - this looks to be mostly a misunderstanding on my part. The Rust code I use is compiled into a Python module, and the Python distribution rules require that openssl is statically linked on Linux. Thinking it would be better to continue to use the system library on macOS, I had updated my Cargo.toml file to be:

[target.'cfg(linux)'.dependencies.reqwest]
version = "0.10"
features = ["json", "socks", "stream", "native-tls-vendored"]

[target.'cfg(not(linux))'.dependencies.reqwest]
version = "0.10"
features = ["json", "socks", "stream"]

This resulted in the Linux build statically linking openssl, and we were using the nightly compiler at the time for other reasons, so I had thought the problem solved. Re-reading that link above, I realize that I had neglected to enable itarget, and so had probably just been vendoring on all platforms instead. Whoops.

I now see that for simple feature lists not gated by platform, cargo raze is adjusting the crate_features argument to match what is in Cargo.toml. So the only issue here is that cargo raze doesn't support the nightly target-specific resolution rules that are off by default, and that's probably a niche enough feature that it's not worth worrying about at the moment.

[UebelAndre]

You could leave this open as a feature request 😄

[dae]

Didn't want to clutter up the tracker with something nobody else may ever ask for :-) If someone else finds this and has the same issue, I can open it again.