Intermittent "feature cannot be used on stable release channel"

[jyn514]

I temporarily got this error trying to build rustix as a dependency:

error[E0554]: `#![feature]` may not be used on the stable release channel
--> /Users/jyn/.local/lib/cargo/registry/src/cf-workers-proxy-9e9.pages.dev-1ecc6299db9ec823/rustix-0.36.4/src/lib.rs:99:26
   |
99 | #![cfg_attr(rustc_attrs, feature(rustc_attrs))]
   |                          ^^^^^^^^^^^^^^^^^^^^

I have unfortunately not been able to reproduce this error; I updated the version of rustix, which I originally thought fixed the issue, but when I downgraded to 0.36.4 I couldn't reproduce it again.

I think the build script needs to have rerun-if-env-changed=RUSTC or something like that? If it helps, my default toolchain is nightly but I have a rust-toolchain file that says to use 1.65.

[jyn514]

cc rust-lang/cargo#10367

[intgr]

FWIW running rm -rf target to delete the cache fixed this issue for me.

[p-kraszewski]

I have this very error popping in my various projects (95% of the time related to rustix). A simple cargo clean is a fix, but it forces me to fully recompile big projects, which is slightly annoying.

Sometimes just adding a new dependency to my projects triggers it.

[sunfishcode]

I submitted #544 in hopes that it may help. However, I don't yet have a reliable way to reproduce the problem locally, so I can't say for sure whether it does.

[jyn514]

I have this very error popping in my various projects (95% of the time related to rustix). A simple cargo clean is a fix, but it forces me to fully recompile big projects, which is slightly annoying.

@p-kraszewski as a workaround, you can use cargo clean -p rustix to only recompile rustix instead of all your dependencies

[sunfishcode]

#544, which may fix this, is now released in version 0.37.

[sunfishcode]

Does anyone who encountered this issue continue to see it with 0.37, or 0.36.11?

[p-kraszewski]

Not encountered within at least the last 2 weeks. Thank you.