--print=native-static-libs is not emitted to stdout, but instead to stderr

[madsmtm]

Running the following:

$ echo "" > empty.rs
$ rustc empty.rs --crate-type=staticlib --print=native-static-libs
note: Link against the following native artifacts when linking against this static library. The order and any duplication can be significant on some platforms.

note: native-static-libs: -lSystem -lc -lm

I.e. it does produce the expected native-static-libs: ... note, but the note is emitted to the stderr stream, instead of stdout, as is done by the other --print=... flags.

I expected to be able to pipe the output to e.g. grep to extract the note, but no such luck:

$ rustc empty.rs --crate-type=staticlib --print=native-static-libs | grep native-static-libs

Meta

rustc --version --verbose:

rustc 1.80.0-nightly (e82c861d7 2024-05-04)
binary: rustc
commit-hash: e82c861d7e5ecd766cb0dab0bf622445dec999dc
commit-date: 2024-05-04
host: aarch64-apple-darwin
release: 1.80.0-nightly
LLVM version: 18.1.4

[madsmtm]

I am unsure how to go about fixing this? Perhaps the solution would just be to emit it to both streams, for backwards compatibility?

[Urgau]

This was also reported on IRLO, https://internals.rust-lang.org/t/print-native-static-libs-to-stdout/17211