Custom linker in ~/.cargo/config.toml is ignored

[JeftavanderHorst]

I have defined a custom linker and archiver in ~/.cargo/config.toml like so:

[target.aarch64-linux-android]
linker = "C:\\Users\\Jefta\\AppData\\Local\\Android\\Sdk\\ndk\\29.0.13846066\\toolchains\\llvm\\prebuilt\\windows-x86_64\\bin\\aarch64-linux-android21-clang.cmd"
ar = "C:\\Users\\Jefta\\AppData\\Local\\Android\\Sdk\\ndk\\29.0.13846066\\toolchains\\llvm\\prebuilt\\windows-x86_64\\bin\\llvm-ar.exe"

This is currently not respected by ring:

warning: [email protected]: Compiler family detection failed due to error: ToolNotFound: failed to find tool "aarch64-linux-android-clang": program not found

Manually setting the TARGET_CC and TARGET_AR environment variables solves the issue.

Although this is not a huge issue, it is a bit annoying to remember to set the env variables every time. Is it possible to use the values defined in config.toml?

I'd be willing to spend some time on a PR given a bit of guidance how to tackle this.

[briansmith]

Your .cargo/config.toml specifies the linker and the archiver but not the C compiler;
It would be awesome if .cargo/config.toml could be extended to allow specifying the C compiler to use, or if cc-rs could support a similar mechanism for choosing the C compiler. But AFAICT right now we have to use environment variables.

[JeftavanderHorst]

That makes sense, thank you