# cat /var/tmp/portage/sys-libs/llvm-libunwind-12.0.0/temp/build.log
 * Package:    sys-libs/llvm-libunwind-12.0.0
 * Repository: gentoo
 * Maintainer: llvm@gentoo.org
 * USE:        abi_x86_32 abi_x86_64 amd64 elibc_glibc kernel_linux userland_GNU
 * FEATURES:   network-sandbox preserve-libs sandbox userpriv usersandbox
 * Unpacking from llvmorg-12.0.0.tar.gz ...
 [ ok ]
 * Working in BUILD_DIR: "/var/tmp/portage/sys-libs/llvm-libunwind-12.0.0/work/llvm-libunwind-12.0.0_build"
 * abi_x86_32.x86: running multilib-minimal_abi_src_configure
 * Working in BUILD_DIR: "/var/tmp/portage/sys-libs/llvm-libunwind-12.0.0/work/llvm-libunwind-12.0.0_build-abi_x86_32.x86"
cmake -C /var/tmp/portage/sys-libs/llvm-libunwind-12.0.0/work/llvm-libunwind-12.0.0_build-abi_x86_32.x86/gentoo_common_config.cmake -G Ninja -DCMAKE_INSTALL_PREFIX=/usr -DLLVM_LIBDIR_SUFFIX= -DLIBUNWIND_ENABLE_ASSERTIONS=no -DLIBUNWIND_ENABLE_STATIC=no -DLLVM_INCLUDE_TESTS=no -DLIBUNWIND_ENABLE_CROSS_UNWINDING=ON -DCMAKE_BUILD_TYPE=RelWithDebInfo -DCMAKE_TOOLCHAIN_FILE=/var/tmp/portage/sys-libs/llvm-libunwind-12.0.0/work/llvm-libunwind-12.0.0_build-abi_x86_32.x86/gentoo_toolchain.cmake  /var/tmp/portage/sys-libs/llvm-libunwind-12.0.0/work/libunwind
loading initial cache file /var/tmp/portage/sys-libs/llvm-libunwind-12.0.0/work/llvm-libunwind-12.0.0_build-abi_x86_32.x86/gentoo_common_config.cmake
-- The C compiler identification is Clang 12.0.0
-- The CXX compiler identification is Clang 12.0.0
-- The ASM compiler identification is Clang
-- Found assembler: /usr/lib/llvm/12/bin/clang
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - failed
-- Check for working C compiler: /usr/lib/llvm/12/bin/clang
-- Check for working C compiler: /usr/lib/llvm/12/bin/clang - broken
CMake Error at /usr/share/cmake/Modules/CMakeTestCCompiler.cmake:66 (message):
  The C compiler

    "/usr/lib/llvm/12/bin/clang"

  is not able to compile a simple test program.

  It fails with the following output:

    Change Dir: /var/tmp/portage/sys-libs/llvm-libunwind-12.0.0/work/llvm-libunwind-12.0.0_build-abi_x86_32.x86/CMakeFiles/CMakeTmp
    
    Run Build Command(s):/usr/bin/ninja cmTC_028d6 && [1/2] Building C object CMakeFiles/cmTC_028d6.dir/testCCompiler.c.o
    [2/2] Linking C executable cmTC_028d6
    FAILED: cmTC_028d6 
    : && /usr/lib/llvm/12/bin/clang -m32 -march=native -O2 -pipe -fuse-ld=lld -rtlib=compiler-rt -unwindlib=libunwind CMakeFiles/cmTC_028d6.dir/testCCompiler.c.o -o cmTC_028d6   && :
    ld.lld: error: unable to find library -l:libunwind.so
    ld.lld: error: unable to find library -l:libunwind.so
    clang-12: error: linker command failed with exit code 1 (use -v to see invocation)
    ninja: build stopped: subcommand failed.
    
    

  

  CMake will not be able to correctly generate this project.
Call Stack (most recent call first):
  CMakeLists.txt:24 (project)


-- Configuring incomplete, errors occurred!
See also "/var/tmp/portage/sys-libs/llvm-libunwind-12.0.0/work/llvm-libunwind-12.0.0_build-abi_x86_32.x86/CMakeFiles/CMakeOutput.log".
See also "/var/tmp/portage/sys-libs/llvm-libunwind-12.0.0/work/llvm-libunwind-12.0.0_build-abi_x86_32.x86/CMakeFiles/CMakeError.log".
 * ERROR: sys-libs/llvm-libunwind-12.0.0::gentoo failed (configure phase):
 *   cmake failed
 * 
 * Call stack:
 *     ebuild.sh, line  127:  Called src_configure
 *   environment, line 3631:  Called cmake-multilib_src_configure
 *   environment, line 1091:  Called multilib-minimal_src_configure
 *   environment, line 2530:  Called multilib_foreach_abi 'multilib-minimal_abi_src_configure'
 *   environment, line 2783:  Called multibuild_foreach_variant '_multilib_multibuild_wrapper' 'multilib-minimal_abi_src_configure'
 *   environment, line 2460:  Called _multibuild_run '_multilib_multibuild_wrapper' 'multilib-minimal_abi_src_configure'
 *   environment, line 2458:  Called _multilib_multibuild_wrapper 'multilib-minimal_abi_src_configure'
 *   environment, line  474:  Called multilib-minimal_abi_src_configure
 *   environment, line 2524:  Called multilib_src_configure
 *   environment, line 3006:  Called cmake_src_configure
 *   environment, line 1346:  Called die
 * The specific snippet of code:
 *       "${CMAKE_BINARY}" "${cmakeargs[@]}" "${CMAKE_USE_DIR}" || die "cmake failed";
 * 
 * If you need support, post the output of `emerge --info '=sys-libs/llvm-libunwind-12.0.0::gentoo'`,
 * the complete build log and the output of `emerge -pqv '=sys-libs/llvm-libunwind-12.0.0::gentoo'`.
 * The complete build log is located at '/var/tmp/portage/sys-libs/llvm-libunwind-12.0.0/temp/build.log'.
 * The ebuild environment file is located at '/var/tmp/portage/sys-libs/llvm-libunwind-12.0.0/temp/environment'.
 * Working directory: '/var/tmp/portage/sys-libs/llvm-libunwind-12.0.0/work/llvm-libunwind-12.0.0_build-abi_x86_32.x86'
 * S: '/var/tmp/portage/sys-libs/llvm-libunwind-12.0.0/work/libunwind'