rust stable 1.78 using 'x86_64-pc-windows-gnu' host tool to build 'thumbv7em-none-eabihf' arm bare metal target got rust-lld failed

[pbl-pw]

Failed reason is can't find 'libgcc_s_seh-1.dll' and 'libwinpthread-1.dll'
when fallback to 1.77.2 or using 'x86_64-pc-windows-msvc' host tool then every thing is ok

[mati865]

Those libraries are provided alongside other Rust binaries:

$ ls ~/.rustup/toolchains/stable-x86_64-pc-windows-gnu/bin/
cargo.exe*         cargo-fmt.exe*      libgcc_s_seh-1.dll*   rustc.exe*                          rustdoc.exe*  rust-gdb*     rust-lldb*
cargo-clippy.exe*  clippy-driver.exe*  libwinpthread-1.dll*  rustc_driver-35a7c4c28db0aaf0.dll*  rustfmt.exe*  rust-gdbgui*  std-a1f74822451877d1.dll*

Note rust-lld is located inside rustlib:

$ file ~/.rustup/toolchains/stable-x86_64-pc-windows-gnu/lib/rustlib/x86_64-pc-windows-gnu/bin/rust-lld.exe
/c/Users/mateusz/.rustup/toolchains/stable-x86_64-pc-windows-gnu/lib/rustlib/x86_64-pc-windows-gnu/bin/rust-lld.exe: PE32+ executable (console) x86-64, for MS Windows, 17 sections

I rust-lld should be called with PATH set to ~/.rustup/toolchains/stable-x86_64-pc-windows-gnu/bin/, or at least used to be. Do you have an example that reproduces the problem? Hopefully, we can bisect it to easily find the problem.

[pbl-pw]

I have tested using clean rust host toolchain installed by rustinit, and just build cortex-m-quickstart, then it reproduce the problem.
note: Cargo.toml in cortex-m-quickstart need change 'package.name' and 'bin.name' before build, because they have '{{' and '}}'

[mati865]

searched nightlies: from nightly-2024-02-01 to nightly-2024-03-16
regressed nightly: nightly-2024-02-22
searched commit range: bb59453...3406ada
regressed commit: 0987e41

bisected with cargo-bisect-rustc v0.6.8

Host triple: x86_64-pc-windows-gnu
Reproduce with:

cargo bisect-rustc --start=1.77.0 --end=1.78.0 --target thumbv7m-none-eabi --prompt -c rust-mingw --preserve --script C:/Program Files/Git/usr/bin/bash.exe -- ./test.sh

Won't be as easy to debug as I hoped.
@weihanglo do you have any idea which change could case it?

EDIT: perhaps rust-lang/cargo#13468?
No idea how to test it without CI builds though.

[weihanglo]

If I understand correctly, when ~/.rustup/toolchains/stable-x86_64-pc-windows-gnu/bin/ is in PATH on Windows, it makes no difference. What the removed code path did was adding that to PATH. In rustup 1.27.1, RUSTUP_WINDOWS_PATH_ADD_BIN was changed to false by default (rust-lang/rustup#3703), so probably the rustup change is related.

@mati865 is it possible for you to add RUSTUP_WINDOWS_PATH_ADD_BIN=true and check it again?
I don't have a Windows machine available at hand :(

Also, could you check if rustc appends host tool bin to PATH? It looks like it but I am not particularly sure.

[weihanglo]

Would you mind sharing the output of rustup --version that shows the version of rustup you are using, @pbl-pw?

[mati865]

Thought it might be important to add; all my tests were made with only ~/.cargo/bin present in PATH:

$ echo $PATH
/c/Users/mateusz/.cargo/bin

If I understand correctly, when ~/.rustup/toolchains/stable-x86_64-pc-windows-gnu/bin/ is in PATH on Windows, it makes no difference.

Yes, but apparently it's not in PATH when tools from ~/.rustup/toolchains/stable-x86_64-pc-windows-gnu/lib/rustlib/x86_64-pc-windows-gnu/bin are called. $ PATH=$PATH:~/.rustup/toolchains/stable-x86_64-pc-windows-gnu/bin cargo +stable b works fine so that sort of confirms it.

In rustup 1.27.1, RUSTUP_WINDOWS_PATH_ADD_BIN was changed to false by default (rust-lang/rustup#3703), so probably the rustup change is related.

@mati865 is it possible for you to add RUSTUP_WINDOWS_PATH_ADD_BIN=true and check it again? I don't have a Windows machine available at hand :(

Adding that env makes no difference:

$ rustup -V
rustup 1.27.1 (54dd3d00f 2024-04-24)
info: This is the version for the rustup toolchain manager, not the rustc compiler.
info: The currently active `rustc` version is `rustc 1.80.0-nightly (a330e4959 2024-06-04)`

$ RUSTUP_WINDOWS_PATH_ADD_BIN=true cargo +stable b
...
error: linking with `rust-lld` failed: exit code: 0xc0000135

Also, could you check if rustc appends host tool bin to PATH? It looks like it but I am not particularly sure.

I can do some builds during the weekend.

Also, could you check if rustc appends host tool bin to PATH? It looks like it but I am not particularly sure.

Judging from that code, it only adds ~/.rustup/toolchains/stable-x86_64-pc-windows-gnu/lib/rustlib/x86_64-pc-windows-gnu/bin.

[weihanglo]

My fault. Should be RUSTUP_WINDOWS_PATH_ADD_BIN=1 not true.

[mati865]

Oh, I had missed that too 😄
RUSTUP_WINDOWS_PATH_ADD_BIN=1 cargo +stable b works fine.