"cargo-warning:Compiler version doesn't include clang or GCC" prints a lot on Ubuntu

[jonathanpallant]

When I'm building Rust (well, Ferrocene), I see a lot of:

cargo-warning:Compiler version doesn't include clang or GCC: "cc" "--version"

This appears to be because Ubuntu 22.04's GCC doesn't report itself as GCC failing this check.

ubuntu@machine:~/work/ferrocene$ cc --version
 cc (Ubuntu 11.4.0-1ubuntu1~22.04) 11.4.0
 Copyright (C) 2021 Free Software Foundation, Inc.
 This is free software; see the source for copying conditions.  There is NO
 warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

ubuntu@machine:~/work/ferrocene$ gcc --version
 gcc (Ubuntu 11.4.0-1ubuntu1~22.04) 11.4.0
 Copyright (C) 2021 Free Software Foundation, Inc.
 This is free software; see the source for copying conditions.  There is NO
 warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

ubuntu@machine:~/work/ferrocene$ clang --version
 Ubuntu clang version 14.0.0-1ubuntu1.1
 Target: x86_64-pc-linux-gnu
 Thread model: posix
 InstalledDir: /usr/bin

ubuntu@machine:~/work/ferrocene$ uname -a
 Linux ip-172-31-17-237 6.2.0-1016-aws #16~22.04.1-Ubuntu SMP Sun Nov  5 20:08:16 UTC 2023 x86_64 x86_64 x86_64 GNU/Linux

ubuntu@machine:~/work/ferrocene$

I'm using cc 1.0.79.

If --version doesn't help, you could consider using cc -v instead?

ubuntu@machine:~/work/ferrocene$ cc -v
 Using built-in specs.
 COLLECT_GCC=cc
 COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/11/lto-wrapper
 OFFLOAD_TARGET_NAMES=nvptx-none:amdgcn-amdhsa
 OFFLOAD_TARGET_DEFAULT=1
 Target: x86_64-linux-gnu
 Configured with: ../src/configure -v --with-pkgversion='Ubuntu 11.4.0-1ubuntu1~22.04' --with-bugurl=file:///usr/share/doc/gcc-11/README.Bugs --enable-languages=c,ada,c++,go,brig,d,fortran,objc,obj-c++,m2 --prefix=/usr --with-gcc-major-version-only --program-suffix=-11 --program-prefix=x86_64-linux-gnu- --enable-shared --enable-linker-build-id --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --libdir=/usr/lib --enable-nls --enable-bootstrap --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --with-default-libstdcxx-abi=new --enable-gnu-unique-object --disable-vtable-verify --enable-plugin --enable-default-pie --with-system-zlib --enable-libphobos-checking=release --with-target-system-zlib=auto --enable-objc-gc=auto --enable-multiarch --disable-werror --enable-cet --with-arch-32=i686 --with-abi=m64 --with-multilib-list=m32,m64,mx32 --enable-multilib --with-tune=generic --enable-offload-targets=nvptx-none=/build/gcc-11-XeT9lY/gcc-11-11.4.0/debian/tmp-nvptx/usr,amdgcn-amdhsa=/build/gcc-11-XeT9lY/gcc-11-11.4.0/debian/tmp-gcn/usr --without-cuda-driver --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu --with-build-config=bootstrap-lto-lean --enable-link-serialization=2
 Thread model: posix
 Supported LTO compression algorithms: zlib zstd
 gcc version 11.4.0 (Ubuntu 11.4.0-1ubuntu1~22.04)

ubuntu@machine:~/work/ferrocene$ gcc -v
 Using built-in specs.
 COLLECT_GCC=gcc
 COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/11/lto-wrapper
 OFFLOAD_TARGET_NAMES=nvptx-none:amdgcn-amdhsa
 OFFLOAD_TARGET_DEFAULT=1
 Target: x86_64-linux-gnu
 Configured with: ../src/configure -v --with-pkgversion='Ubuntu 11.4.0-1ubuntu1~22.04' --with-bugurl=file:///usr/share/doc/gcc-11/README.Bugs --enable-languages=c,ada,c++,go,brig,d,fortran,objc,obj-c++,m2 --prefix=/usr --with-gcc-major-version-only --program-suffix=-11 --program-prefix=x86_64-linux-gnu- --enable-shared --enable-linker-build-id --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --libdir=/usr/lib --enable-nls --enable-bootstrap --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --with-default-libstdcxx-abi=new --enable-gnu-unique-object --disable-vtable-verify --enable-plugin --enable-default-pie --with-system-zlib --enable-libphobos-checking=release --with-target-system-zlib=auto --enable-objc-gc=auto --enable-multiarch --disable-werror --enable-cet --with-arch-32=i686 --with-abi=m64 --with-multilib-list=m32,m64,mx32 --enable-multilib --with-tune=generic --enable-offload-targets=nvptx-none=/build/gcc-11-XeT9lY/gcc-11-11.4.0/debian/tmp-nvptx/usr,amdgcn-amdhsa=/build/gcc-11-XeT9lY/gcc-11-11.4.0/debian/tmp-gcn/usr --without-cuda-driver --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu --with-build-config=bootstrap-lto-lean --enable-link-serialization=2
 Thread model: posix
 Supported LTO compression algorithms: zlib zstd
 gcc version 11.4.0 (Ubuntu 11.4.0-1ubuntu1~22.04)

ubuntu@machine:~/work/ferrocene$ clang -v
 Ubuntu clang version 14.0.0-1ubuntu1.1
 Target: x86_64-pc-linux-gnu
 Thread model: posix
 InstalledDir: /usr/bin
 Found candidate GCC installation: /usr/bin/../lib/gcc/x86_64-linux-gnu/11
 Selected GCC installation: /usr/bin/../lib/gcc/x86_64-linux-gnu/11
 Candidate multilib: .;@m64
 Selected multilib: .;@m64

ubuntu@machine:~/work/ferrocene$

Other options include looking for the "Free Software Foundation" copyright (that will always mean it's gcc, surely), or the string cc (Ubuntu.

Clang's output remains constant, no matter whether it is called as clang or cc.