build-std seems broken in nightly (rustc 1.71.0-nightly (74c482104 2023-05-04))

[gamozolabs]

When I attempt to build (seemingly anything) with -Zbuild-std=core on nightly I get an error with package test not having the feature backtrace.

This seems to affect a random sampling of targets I picked, it seems more fundamental than that:

pleb@gamey ~/regression $ cat src/main.rs 

#![no_std]
#![no_main]

#[panic_handler]
fn panic(pi: &core::panic::PanicInfo) -> ! {
    loop {}
}

#[no_mangle]
extern fn efi_main() {
}

pleb@gamey ~/regression $ cat Cargo.toml 
[package]
name = "regression"
version = "0.1.0"
edition = "2021"

# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html

[dependencies]
pleb@gamey ~/regression $ cargo build --target powerpc-unknown-freebsd -Zbuild-std=core
error: Package `test v0.0.0 (/home/pleb/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/test)` does not have the feature `backtrace`
pleb@gamey ~/regression $ cargo build --target x86_64-unknown-none -Zbuild-std=core
error: Package `test v0.0.0 (/home/pleb/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/test)` does not have the feature `backtrace`
pleb@gamey ~/regression $ cargo build --target x86_64-unknown-uefi -Zbuild-std=core
error: Package `test v0.0.0 (/home/pleb/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/test)` does not have the feature `backtrace`

[jyn514]

Probably caused by #108865

[mqudsi]

Yes, #108865 is the one behind this. It should be fixed by rust-lang/cargo#12088, probably in the next cargo nightly build.

[ehuss]

I believe this is now fixed in the latest nightly.