Cross compile for arm-unknown-linux-musleabihf: configure: error: C compiler cannot create executables

[olegantonyan]

.cargo/config

[target.arm-unknown-linux-musleabihf]
linker = "/home/oleg/bin/buildroot-2017.02.10/output/host/usr/bin/arm-buildroot-linux-musleabihf-gcc-5.4.0.br_real"

cargo build --target=arm-unknown-linux-musleabihf
yields an error:

running: "sh" "/home/oleg/.cargo/registry/src/github.com-1ecc6299db9ec823/backtrace-sys-0.1.16/src/libbacktrace/configure" "--with-pic" "--disable-multilib" "--disable-shared" "--disable-host-shared" "--host=arm-unknown-linux-musleabihf" "--build=x86_64-unknown-linux-gnu"
configure: loading site script /usr/share/site/x86_64-unknown-linux-gnu
checking build system type... x86_64-unknown-linux-gnu
checking host system type... arm-unknown-linux-musleabihf
checking target system type... arm-unknown-linux-musleabihf
checking for arm-unknown-linux-musleabihf-gcc... arm-linux-musleabihf-gcc
checking for C compiler default output file name... 

--- stderr
configure: error: in `/home/oleg/projects/bbb_webui/target/arm-unknown-linux-musleabihf/debug/build/backtrace-sys-2f65fb215f9723a3/out':
configure: error: C compiler cannot create executables
See `config.log' for more details.

To make it work I have to specify CC through env:
CC=/home/oleg/bin/buildroot-2017.02.10/output/host/usr/bin/arm-buildroot-linux-musleabihf-gcc-5.4.0.br_real cargo build --target=arm-unknown-linux-musleabihf

Don't know exactly how to fix it properly, but anyway.
rustc 1.26.0-nightly (322d7f7b9 2018-02-25)
cargo 0.26.0-nightly (1d6dfea44 2018-01-26)

[alexcrichton]

Thanks for the report! Unfortunately I think this is due to rust-lang/cc-rs#82, you'll need to specify the compiler in two locations