Fix CC pointing to wrong compiler

[antoinefaure]

Hi,

Thanks for this project :)

I encountered an issue when trying to cross compile vector using Yocto Scarthgap for an aarch64 platform (e.g. Raspberry Pi 4) :

| error: failed to run custom build command for `krb5-src v0.3.2+1.19.2`
| 
| Caused by:
|   process didn't exit successfully: `/workspaces/omnios_rust_bin/build/tmp/work/cortexa72-poky-linux/vector/0.44.0/target/release/build/krb5-src-7d691da815ca739d/build-script-build` (exit status: 101)
|   --- stdout
|   checking for aarch64-unknown-linux-gnu-gcc... /workspaces/omnios_rust_bin/build/tmp/work/cortexa72-poky-linux/vector/0.44.0/wrappers/cc-native-wrapper.sh
|   checking whether the C compiler works... no
| 
|   --- stderr
|   configure: error: in `/workspaces/omnios_rust_bin/build/tmp/work/cortexa72-poky-linux/vector/0.44.0/target/aarch64-unknown-linux-gnu/release/build/krb5-src-7712872c0cb50834/out/build':
|   configure: error: C compiler cannot create executables

By the look of it the build system was trying to use the gcc from the host (in my case it's running in Docker but that's irrelevant) and was therefore failing. I have changed the values set in CC and CXX to match what is done in cargo_bin_do_configure :

echo "${CC} \"\$@\"" >>"${WRAPPER_DIR}/cc-wrapper.sh"
echo "${CXX} \"\$@\"" >>"${WRAPPER_DIR}/cxx-wrapper.sh"

And with this the build is successful.

Please let me know if this is not the right approach.

Thanks,
Antoine

[antoinefaure]

The LD variable may also need to be changed to use linker-wrapper.sh. From my understanding Yocto will set CC to the compiler that we need (if building a native recipe then gcc, if cross compiling then the appropriate compiler).
Any opinion on the matter @eldruin ?

[eldruin]

Sounds good to me, thank you!