qemu-binfmt-service failing to identify compilers

[Brett Gilio <brettg@gnu.org>]

Hi all,

When I try to test guix builds for other architectures using the
qemu-binfmt-service and the --system flag, the configuration step is
failing to identify the compiler with the CMake build system. I did some
investigating, and it appears this is a failing test in CMake itself but
it causes packages to fail on build. This seems to only be the case when
compiling for foreign architectures, as building on the true
architecture seems to work (as in the Guix CI).

--8<---------------cut here---------------start------------->8---
CMake Error at /gnu/store/8aamffn0azz4jx4m18pzw4k14sr437ly-cmake-minimal-3.16.5/share/cmake-3.16/Modules/CMakeCompilerIdDetection.cmake:26 (list):
  list sub-command REMOVE_ITEM requires two or more arguments.
Call Stack (most recent call first):
  /gnu/store/8aamffn0azz4jx4m18pzw4k14sr437ly-cmake-minimal-3.16.5/share/cmake-3.16/Modules/CMakeDetermineCompilerId.cmake:211 (compiler_id_detection)
  /gnu/store/8aamffn0azz4jx4m18pzw4k14sr437ly-cmake-minimal-3.16.5/share/cmake-3.16/Modules/CMakeDetermineCompilerId.cmake:230 (CMAKE_DETERMINE_COMPILER_ID_WRITE)
  /gnu/store/8aamffn0azz4jx4m18pzw4k14sr437ly-cmake-minimal-3.16.5/share/cmake-3.16/Modules/CMakeDetermineCompilerId.cmake:32 (CMAKE_DETERMINE_COMPILER_ID_BUILD)
  /gnu/store/8aamffn0azz4jx4m18pzw4k14sr437ly-cmake-minimal-3.16.5/share/cmake-3.16/Modules/CMakeDetermineCXXCompiler.cmake:111 (CMAKE_DETERMINE_COMPILER_ID)
  CMakeLists.txt:5 (project)


-- The CXX compiler identification is unknown
-- Check for working C compiler: /gnu/store/z8954h4nvgxwcyy2in8c1l11g199m2yb-gcc-7.5.0/bin/gcc
-- Check for working C compiler: /gnu/store/z8954h4nvgxwcyy2in8c1l11g199m2yb-gcc-7.5.0/bin/gcc -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Check for working CXX compiler: /gnu/store/z8954h4nvgxwcyy2in8c1l11g199m2yb-gcc-7.5.0/bin/c++
-- Check for working CXX compiler: /gnu/store/z8954h4nvgxwcyy2in8c1l11g199m2yb-gcc-7.5.0/bin/c++ -- works
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
Unknown C compiler.  
--8<---------------cut here---------------end--------------->8---

when keeping the failing build, this is what I find in the CMakeError.log.

--8<---------------cut here---------------start------------->8---
Compiling the C compiler identification source file "CMakeCCompilerId.c" failed.
Compiler: /gnu/store/z8954h4nvgxwcyy2in8c1l11g199m2yb-gcc-7.5.0/bin/gcc 
Build flags: 
Id flags:  

The output was:
1
CMakeCCompilerId.c:20:52: error: expected ‘,’ or ‘;’ before ‘COMPILER_ID’
 char const* info_compiler = "INFO" ":" "compiler[" COMPILER_ID "]";
                                                    ^~~~~~~~~~~
--8<---------------cut here---------------end--------------->8---

--8<---------------cut here---------------start------------->8---
Compiling the C compiler identification source file "CMakeCCompilerId.c" failed.
Compiler: /gnu/store/z8954h4nvgxwcyy2in8c1l11g199m2yb-gcc-7.5.0/bin/gcc 
Build flags: 
Id flags: --target=arm-arm-none-eabi;-mcpu=cortex-m3 

The output was:
1
gcc: error: unrecognized command line option ‘--target=arm-arm-none-eabi’
--8<---------------cut here---------------end--------------->8---

I am getting this error on both SWI-Prolog and Lean packages, both of
which I have needed to investigate on armhf and i686 because of failures
on those architectures.

I am not entirely sure how to proceed with these issues.

Any help? Thanks.

Brett Gilio