Checking whether the ASM compiler is GNU using "--version" did not match "(GNU assembler)|(GCC)|(Free Software Foundation)":
clang version 4.0.1 (tags/RELEASE_401/final)
Target: x86_64-pc-linux-gnu
Thread model: posix
InstalledDir: /usr/lib/llvm/4/bin
Checking whether the ASM compiler is HP using "-V" did not match "HP C":
clang-4.0: error: argument to '-V' is missing (expected 1 value)
clang-4.0: error: no input files
Checking whether the ASM compiler is Intel using "--version" did not match "(ICC)":
clang version 4.0.1 (tags/RELEASE_401/final)
Target: x86_64-pc-linux-gnu
Thread model: posix
InstalledDir: /usr/lib/llvm/4/bin
Checking whether the ASM compiler is SunPro using "-V" did not match "Sun C":
clang-4.0: error: argument to '-V' is missing (expected 1 value)
clang-4.0: error: no input files
Checking whether the ASM compiler is XL using "-qversion" did not match "XL C":
clang-4.0: error: unknown argument: '-qversion'
clang-4.0: error: no input files
Checking whether the ASM compiler is MSVC using "/?" did not match "Microsoft":
clang-4.0: error: no such file or directory: '/?'
clang-4.0: error: no input files
Checking whether the ASM compiler is TI using "-h" did not match "Texas Instruments":
clang-4.0: error: unknown argument: '-h'
clang-4.0: error: no input files
Checking whether the ASM compiler is GNU using "--version" did not match "(GNU assembler)|(GCC)|(Free Software Foundation)":
clang version 4.0.1 (tags/RELEASE_401/final)
Target: x86_64-pc-linux-gnu
Thread model: posix
InstalledDir: /usr/lib/llvm/4/bin
Checking whether the ASM compiler is IAR using "" did not match "IAR Assembler":
clang-4.0: error: no input files
Checking whether the ASM compiler is ARMCC using "" did not match "(ARM Compiler)|(ARM Assembler)":
clang-4.0: error: no input files
Checking whether the ASM compiler is NASM using "-v" did not match "(NASM version)":
clang version 4.0.1 (tags/RELEASE_401/final)
Target: x86_64-pc-linux-gnu
Thread model: posix
InstalledDir: /usr/lib/llvm/4/bin
Selected GCC installation: /usr/lib/gcc/x86_64-pc-linux-gnu/6.4.0
Candidate multilib: .;@m64
Candidate multilib: 32;@m32
Selected multilib: .;@m64
Checking whether the ASM compiler is YASM using "--version" did not match "(yasm)":
clang version 4.0.1 (tags/RELEASE_401/final)
Target: x86_64-pc-linux-gnu
Thread model: posix
InstalledDir: /usr/lib/llvm/4/bin
Determining if the C compiler works failed with the following output:
Change Dir: /var/tmp/portage/sys-libs/compiler-rt-4.0.1/work/compiler-rt-4.0.1_build/CMakeFiles/CMakeTmp

Run Build Command:"/usr/bin/ninja" "cmTC_d0a4d"
[1/2] Building C object CMakeFiles/cmTC_d0a4d.dir/testCCompiler.c.o
[2/2] Linking C executable cmTC_d0a4d
FAILED: cmTC_d0a4d 
: && /usr/lib/llvm/4/bin/x86_64-pc-linux-gnu-clang -O2 -pipe -march=native -Wall  -nodefaultlibs   -rdynamic CMakeFiles/cmTC_d0a4d.dir/testCCompiler.c.o  -o cmTC_d0a4d   && :
/usr/lib/gcc/x86_64-pc-linux-gnu/6.4.0/../../../../lib64/crt1.o: In function `_start':
(.text+0x12): undefined reference to `__libc_csu_fini'
/usr/lib/gcc/x86_64-pc-linux-gnu/6.4.0/../../../../lib64/crt1.o: In function `_start':
(.text+0x19): undefined reference to `__libc_csu_init'
/usr/lib/gcc/x86_64-pc-linux-gnu/6.4.0/../../../../lib64/crt1.o: In function `_start':
(.text+0x26): undefined reference to `__libc_start_main'
clang-4.0: error: linker command failed with exit code 1 (use -v to see invocation)
ninja: build stopped: subcommand failed.