ld in fake-toolchain must work properly

[catror]

I am trying to use YCM-Generator for leveldb. And my cmake version is 3.12.4, my clang version is 7.0, my operating system is ubuntu 16.04.

When I executed config_gen.py, some cmake errors occurred. So I checked the error log and found that cmake tried to link an executable by executing the following command:

"${path_to_fake-toolchain}/Unix/ld" -z relro --hash-style=gnu --eh-frame-hdr -m elf_x86_64 -dynamic-linker /lib64/ld-linux-x86-64.so.2 -o cmTC_fe463 /usr/lib/gcc/x86_64-linux-gnu/5.4.0/../../../x86_64-linux-gnu/crt1.o /usr/lib/gcc/x86_64-linux-gnu/5.4.0/../../../x86_64-linux-gnu/crti.o /usr/lib/gcc/x86_64-linux-gnu/5.4.0/crtbegin.o -L/usr/lib/gcc/x86_64-linux-gnu/5.4.0 -L/usr/lib/gcc/x86_64-linux-gnu/5.4.0/../../../x86_64-linux-gnu -L/lib/x86_64-linux-gnu -L/lib/../lib64 -L/usr/lib/x86_64-linux-gnu -L/usr/lib/gcc/x86_64-linux-gnu/5.4.0/../../.. -L/usr/local/bin/../lib -L/lib -L/usr/lib CMakeFiles/cmTC_fe463.dir/CMakeCXXCompilerABI.cpp.o -lstdc++ -lm -lgcc_s -lgcc -lc -lgcc_s -lgcc /usr/lib/gcc/x86_64-linux-gnu/5.4.0/crtend.o /usr/lib/gcc/x86_64-linux-gnu/5.4.0/../../../x86_64-linux-gnu/crtn.o

Then, I tried to modify ld in fake-toolchain to make it work properly on my operating system.

#!/bin/sh
/usr/bin/ld $@

After that, I executed config_gen.py again and it works fine.

[rdnetto]

When we invoke config_gen.py for Cmake, there are two stages:

• the generation of the makefiles. During this we use a real compiler, as it's needed for cmake to correctly detect the compiler settings.
• actually building the project. During this, we stub out the compiler and log the arguments it's invoked with.

We currently stub out ld completely to simply exit 0 because a real linker would fail, since the object files wouldn't exist given the compiler is stubbed out. Are you sure that your build is invoking the clang from the fake-toolchain, and not the real one?

[catror]

Yes, I am sure. The errors occurred in the first stage.
I tested the first stage manually, all the commands I executed:

mkdir /tmp/leveldb
cd /tmp/leveldb/
git clone https://github.com/google/leveldb.git
export PATH=~/.vim/plugged/YCM-Generator/fake-toolchain/Unix/:$PATH
export CC=clang
export CXX=clang++
export YCM_CONFIG_GEN_CC_PASSTHROUGH=/usr/local/bin/clang
export YCM_CONFIG_GEN_CXX_PASSTHROUGH=/usr/local/bin/clang++
/usr/local/bin/cmake /tmp/leveldb/leveldb/

output of cmake:

-- The C compiler identification is Clang 7.0.0
-- The CXX compiler identification is Clang 7.0.0
-- Check for working C compiler: /home/catror/.vim/plugged/YCM-Generator/fake-toolchain/Unix/clang
-- Check for working C compiler: /home/catror/.vim/plugged/YCM-Generator/fake-toolchain/Unix/clang -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - failed
-- Detecting C compile features
-- Detecting C compile features - failed
-- Check for working CXX compiler: /home/catror/.vim/plugged/YCM-Generator/fake-toolchain/Unix/clang++
-- Check for working CXX compiler: /home/catror/.vim/plugged/YCM-Generator/fake-toolchain/Unix/clang++ -- works
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - failed
-- Detecting CXX compile features
-- Detecting CXX compile features - failed
-- Check if the system is big endian
-- Searching 16 bit integer
-- Looking for sys/types.h
-- Looking for sys/types.h - found
-- Looking for stdint.h
-- Looking for stdint.h - found
-- Looking for stddef.h
-- Looking for stddef.h - found
-- Check size of unsigned short
CMake Error at /usr/local/share/cmake-3.12/Modules/CheckTypeSize.cmake:116 (try_compile):
Cannot copy output executable

''

to destination specified by COPY_FILE:

'/tmp/leveldb/CMakeFiles/CheckTypeSize/CMAKE_SIZEOF_UNSIGNED_SHORT.bin'

Unable to find the executable at any of:

/tmp/leveldb/CMakeFiles/CMakeTmp/cmTC_88665
/tmp/leveldb/CMakeFiles/CMakeTmp/Debug/cmTC_88665
/tmp/leveldb/CMakeFiles/CMakeTmp/Development/cmTC_88665

Call Stack (most recent call first):
/usr/local/share/cmake-3.12/Modules/CheckTypeSize.cmake:241 (__check_type_size_impl)
/usr/local/share/cmake-3.12/Modules/TestBigEndian.cmake:32 (CHECK_TYPE_SIZE)
CMakeLists.txt:23 (test_big_endian)

-- Check size of unsigned int
CMake Error at /usr/local/share/cmake-3.12/Modules/CheckTypeSize.cmake:116 (try_compile):
Cannot copy output executable

''

to destination specified by COPY_FILE:

'/tmp/leveldb/CMakeFiles/CheckTypeSize/CMAKE_SIZEOF_UNSIGNED_INT.bin'

Unable to find the executable at any of:

/tmp/leveldb/CMakeFiles/CMakeTmp/cmTC_d4fc0
/tmp/leveldb/CMakeFiles/CMakeTmp/Debug/cmTC_d4fc0
/tmp/leveldb/CMakeFiles/CMakeTmp/Development/cmTC_d4fc0

Call Stack (most recent call first):
/usr/local/share/cmake-3.12/Modules/CheckTypeSize.cmake:241 (__check_type_size_impl)
/usr/local/share/cmake-3.12/Modules/TestBigEndian.cmake:37 (CHECK_TYPE_SIZE)
CMakeLists.txt:23 (test_big_endian)

-- Check size of unsigned long
CMake Error at /usr/local/share/cmake-3.12/Modules/CheckTypeSize.cmake:116 (try_compile):
Cannot copy output executable

''

to destination specified by COPY_FILE:

'/tmp/leveldb/CMakeFiles/CheckTypeSize/CMAKE_SIZEOF_UNSIGNED_LONG.bin'

Unable to find the executable at any of:

/tmp/leveldb/CMakeFiles/CMakeTmp/cmTC_63119
/tmp/leveldb/CMakeFiles/CMakeTmp/Debug/cmTC_63119
/tmp/leveldb/CMakeFiles/CMakeTmp/Development/cmTC_63119

Call Stack (most recent call first):
/usr/local/share/cmake-3.12/Modules/CheckTypeSize.cmake:241 (__check_type_size_impl)
/usr/local/share/cmake-3.12/Modules/TestBigEndian.cmake:44 (CHECK_TYPE_SIZE)
CMakeLists.txt:23 (test_big_endian)

CMake Error at /usr/local/share/cmake-3.12/Modules/TestBigEndian.cmake:49 (message):
no suitable type found
Call Stack (most recent call first):
CMakeLists.txt:23 (test_big_endian)

-- Configuring incomplete, errors occurred!
See also "/tmp/leveldb/CMakeFiles/CMakeOutput.log".
See also "/tmp/leveldb/CMakeFiles/CMakeError.log".

CMakeOutput.log

The system is: Linux - 4.15.0-39-generic - x86_64
Compiling the C compiler identification source file "CMakeCCompilerId.c" succeeded.
Compiler: /home/catror/.vim/plugged/YCM-Generator/fake-toolchain/Unix/clang
Build flags:
Id flags:

The output was:
0

Compiling the C compiler identification source file "CMakeCCompilerId.c" succeeded.
Compiler: /home/catror/.vim/plugged/YCM-Generator/fake-toolchain/Unix/clang
Build flags:
Id flags: -c

The output was:
0

Compilation of the C compiler identification source "CMakeCCompilerId.c" produced "CMakeCCompilerId.o"

The C compiler identification is Clang, found in "/tmp/leveldb/CMakeFiles/3.12.4/CompilerIdC/CMakeCCompilerId.o"

Compiling the CXX compiler identification source file "CMakeCXXCompilerId.cpp" succeeded.
Compiler: /home/catror/.vim/plugged/YCM-Generator/fake-toolchain/Unix/clang++
Build flags:
Id flags:

The output was:
0

Compiling the CXX compiler identification source file "CMakeCXXCompilerId.cpp" succeeded.
Compiler: /home/catror/.vim/plugged/YCM-Generator/fake-toolchain/Unix/clang++
Build flags:
Id flags: -c

The output was:
0

Compilation of the CXX compiler identification source "CMakeCXXCompilerId.cpp" produced "CMakeCXXCompilerId.o"

The CXX compiler identification is Clang, found in "/tmp/leveldb/CMakeFiles/3.12.4/CompilerIdCXX/CMakeCXXCompilerId.o"

Determining if the C compiler works passed with the following output:
Change Dir: /tmp/leveldb/CMakeFiles/CMakeTmp

Run Build Command:"/usr/bin/make" "cmTC_142fe/fast"
/usr/bin/make -f CMakeFiles/cmTC_142fe.dir/build.make CMakeFiles/cmTC_142fe.dir/build
make[1]: Entering directory '/tmp/leveldb/CMakeFiles/CMakeTmp'
Building C object CMakeFiles/cmTC_142fe.dir/testCCompiler.c.o
/home/catror/.vim/plugged/YCM-Generator/fake-toolchain/Unix/clang -o CMakeFiles/cmTC_142fe.dir/testCCompiler.c.o -c /tmp/leveldb/CMakeFiles/CMakeTmp/testCCompiler.c
Linking C executable cmTC_142fe
/usr/local/bin/cmake -E cmake_link_script CMakeFiles/cmTC_142fe.dir/link.txt --verbose=1
/home/catror/.vim/plugged/YCM-Generator/fake-toolchain/Unix/clang CMakeFiles/cmTC_142fe.dir/testCCompiler.c.o -o cmTC_142fe
make[1]: Leaving directory '/tmp/leveldb/CMakeFiles/CMakeTmp'

Determining if the CXX compiler works passed with the following output:
Change Dir: /tmp/leveldb/CMakeFiles/CMakeTmp

Run Build Command:"/usr/bin/make" "cmTC_2476e/fast"
/usr/bin/make -f CMakeFiles/cmTC_2476e.dir/build.make CMakeFiles/cmTC_2476e.dir/build
make[1]: Entering directory '/tmp/leveldb/CMakeFiles/CMakeTmp'
Building CXX object CMakeFiles/cmTC_2476e.dir/testCXXCompiler.cxx.o
/home/catror/.vim/plugged/YCM-Generator/fake-toolchain/Unix/clang++ -o CMakeFiles/cmTC_2476e.dir/testCXXCompiler.cxx.o -c /tmp/leveldb/CMakeFiles/CMakeTmp/testCXXCompiler.cxx
Linking CXX executable cmTC_2476e
/usr/local/bin/cmake -E cmake_link_script CMakeFiles/cmTC_2476e.dir/link.txt --verbose=1
/home/catror/.vim/plugged/YCM-Generator/fake-toolchain/Unix/clang++ CMakeFiles/cmTC_2476e.dir/testCXXCompiler.cxx.o -o cmTC_2476e
make[1]: Leaving directory '/tmp/leveldb/CMakeFiles/CMakeTmp'

Determining if the include file sys/types.h exists passed with the following output:
Change Dir: /tmp/leveldb/CMakeFiles/CMakeTmp

Run Build Command:"/usr/bin/make" "cmTC_694f9/fast"
/usr/bin/make -f CMakeFiles/cmTC_694f9.dir/build.make CMakeFiles/cmTC_694f9.dir/build
make[1]: Entering directory '/tmp/leveldb/CMakeFiles/CMakeTmp'
Building C object CMakeFiles/cmTC_694f9.dir/CheckIncludeFile.c.o
/home/catror/.vim/plugged/YCM-Generator/fake-toolchain/Unix/clang -std=c11 -o CMakeFiles/cmTC_694f9.dir/CheckIncludeFile.c.o -c /tmp/leveldb/CMakeFiles/CMakeTmp/CheckIncludeFile.c
Linking C executable cmTC_694f9
/usr/local/bin/cmake -E cmake_link_script CMakeFiles/cmTC_694f9.dir/link.txt --verbose=1
/home/catror/.vim/plugged/YCM-Generator/fake-toolchain/Unix/clang CMakeFiles/cmTC_694f9.dir/CheckIncludeFile.c.o -o cmTC_694f9
make[1]: Leaving directory '/tmp/leveldb/CMakeFiles/CMakeTmp'

Determining if the include file stdint.h exists passed with the following output:
Change Dir: /tmp/leveldb/CMakeFiles/CMakeTmp

Run Build Command:"/usr/bin/make" "cmTC_595fd/fast"
/usr/bin/make -f CMakeFiles/cmTC_595fd.dir/build.make CMakeFiles/cmTC_595fd.dir/build
make[1]: Entering directory '/tmp/leveldb/CMakeFiles/CMakeTmp'
Building C object CMakeFiles/cmTC_595fd.dir/CheckIncludeFile.c.o
/home/catror/.vim/plugged/YCM-Generator/fake-toolchain/Unix/clang -std=c11 -o CMakeFiles/cmTC_595fd.dir/CheckIncludeFile.c.o -c /tmp/leveldb/CMakeFiles/CMakeTmp/CheckIncludeFile.c
Linking C executable cmTC_595fd
/usr/local/bin/cmake -E cmake_link_script CMakeFiles/cmTC_595fd.dir/link.txt --verbose=1
/home/catror/.vim/plugged/YCM-Generator/fake-toolchain/Unix/clang CMakeFiles/cmTC_595fd.dir/CheckIncludeFile.c.o -o cmTC_595fd
make[1]: Leaving directory '/tmp/leveldb/CMakeFiles/CMakeTmp'

Determining if the include file stddef.h exists passed with the following output:
Change Dir: /tmp/leveldb/CMakeFiles/CMakeTmp

Run Build Command:"/usr/bin/make" "cmTC_e3bc2/fast"
/usr/bin/make -f CMakeFiles/cmTC_e3bc2.dir/build.make CMakeFiles/cmTC_e3bc2.dir/build
make[1]: Entering directory '/tmp/leveldb/CMakeFiles/CMakeTmp'
Building C object CMakeFiles/cmTC_e3bc2.dir/CheckIncludeFile.c.o
/home/catror/.vim/plugged/YCM-Generator/fake-toolchain/Unix/clang -std=c11 -o CMakeFiles/cmTC_e3bc2.dir/CheckIncludeFile.c.o -c /tmp/leveldb/CMakeFiles/CMakeTmp/CheckIncludeFile.c
Linking C executable cmTC_e3bc2
/usr/local/bin/cmake -E cmake_link_script CMakeFiles/cmTC_e3bc2.dir/link.txt --verbose=1
/home/catror/.vim/plugged/YCM-Generator/fake-toolchain/Unix/clang CMakeFiles/cmTC_e3bc2.dir/CheckIncludeFile.c.o -o cmTC_e3bc2
make[1]: Leaving directory '/tmp/leveldb/CMakeFiles/CMakeTmp'

CMakeError.log

Compilation of the C compiler identification source "CMakeCCompilerId.c" did not produce an executable in "/tmp/leveldb/CMakeFiles/3.12.4/CompilerIdC".

Compilation of the CXX compiler identification source "CMakeCXXCompilerId.cpp" did not produce an executable in "/tmp/leveldb/CMakeFiles/3.12.4/CompilerIdCXX".

Detecting C compiler ABI info failed to compile with the following output:
Change Dir: /tmp/leveldb/CMakeFiles/CMakeTmp

Run Build Command:"/usr/bin/make" "cmTC_79a4f/fast"
/usr/bin/make -f CMakeFiles/cmTC_79a4f.dir/build.make CMakeFiles/cmTC_79a4f.dir/build
make[1]: Entering directory '/tmp/leveldb/CMakeFiles/CMakeTmp'
Building C object CMakeFiles/cmTC_79a4f.dir/CMakeCCompilerABI.c.o
/home/catror/.vim/plugged/YCM-Generator/fake-toolchain/Unix/clang -o CMakeFiles/cmTC_79a4f.dir/CMakeCCompilerABI.c.o -c /usr/local/share/cmake-3.12/Modules/CMakeCCompilerABI.c
Linking C executable cmTC_79a4f
/usr/local/bin/cmake -E cmake_link_script CMakeFiles/cmTC_79a4f.dir/link.txt --verbose=1
/home/catror/.vim/plugged/YCM-Generator/fake-toolchain/Unix/clang -v CMakeFiles/cmTC_79a4f.dir/CMakeCCompilerABI.c.o -o cmTC_79a4f
clang version 7.0.0 (tags/RELEASE_700/final)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /usr/local/bin
Found candidate GCC installation: /usr/lib/gcc/i686-linux-gnu/5
Found candidate GCC installation: /usr/lib/gcc/i686-linux-gnu/5.4.0
Found candidate GCC installation: /usr/lib/gcc/i686-linux-gnu/6
Found candidate GCC installation: /usr/lib/gcc/i686-linux-gnu/6.0.0
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/5
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/5.4.0
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/6
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/6.0.0
Selected GCC installation: /usr/lib/gcc/x86_64-linux-gnu/5.4.0
Candidate multilib: .;@m64
Selected multilib: .;@m64
"/home/catror/.vim/plugged/YCM-Generator/fake-toolchain/Unix/ld" -z relro --hash-style=gnu --eh-frame-hdr -m elf_x86_64 -dynamic-linker /lib64/ld-linux-x86-64.so.2 -o cmTC_79a4f /usr/lib/gcc/x86_64-linux-gnu/5.4.0/../../../x86_64-linux-gnu/crt1.o /usr/lib/gcc/x86_64-linux-gnu/5.4.0/../../../x86_64-linux-gnu/crti.o /usr/lib/gcc/x86_64-linux-gnu/5.4.0/crtbegin.o -L/usr/lib/gcc/x86_64-linux-gnu/5.4.0 -L/usr/lib/gcc/x86_64-linux-gnu/5.4.0/../../../x86_64-linux-gnu -L/lib/x86_64-linux-gnu -L/lib/../lib64 -L/usr/lib/x86_64-linux-gnu -L/usr/lib/gcc/x86_64-linux-gnu/5.4.0/../../.. -L/usr/local/bin/../lib -L/lib -L/usr/lib CMakeFiles/cmTC_79a4f.dir/CMakeCCompilerABI.c.o -lgcc --as-needed -lgcc_s --no-as-needed -lc -lgcc --as-needed -lgcc_s --no-as-needed /usr/lib/gcc/x86_64-linux-gnu/5.4.0/crtend.o /usr/lib/gcc/x86_64-linux-gnu/5.4.0/../../../x86_64-linux-gnu/crtn.o
make[1]: Leaving directory '/tmp/leveldb/CMakeFiles/CMakeTmp'

Cannot copy output executable
''
to destination specified by COPY_FILE:
'/tmp/leveldb/CMakeFiles/3.12.4/CMakeDetermineCompilerABI_C.bin'
Unable to find the executable at any of:
/tmp/leveldb/CMakeFiles/CMakeTmp/cmTC_79a4f
/tmp/leveldb/CMakeFiles/CMakeTmp/Debug/cmTC_79a4f
/tmp/leveldb/CMakeFiles/CMakeTmp/Development/cmTC_79a4f

Detecting C [-std=c11] compiler features failed to compile with the following output:
Change Dir: /tmp/leveldb/CMakeFiles/CMakeTmp

Run Build Command:"/usr/bin/make" "cmTC_eb9e9/fast"
/usr/bin/make -f CMakeFiles/cmTC_eb9e9.dir/build.make CMakeFiles/cmTC_eb9e9.dir/build
make[1]: Entering directory '/tmp/leveldb/CMakeFiles/CMakeTmp'
Building C object CMakeFiles/cmTC_eb9e9.dir/feature_tests.c.o
/home/catror/.vim/plugged/YCM-Generator/fake-toolchain/Unix/clang -std=c11 -o CMakeFiles/cmTC_eb9e9.dir/feature_tests.c.o -c /tmp/leveldb/CMakeFiles/feature_tests.c
Linking C executable cmTC_eb9e9
/usr/local/bin/cmake -E cmake_link_script CMakeFiles/cmTC_eb9e9.dir/link.txt --verbose=1
/home/catror/.vim/plugged/YCM-Generator/fake-toolchain/Unix/clang CMakeFiles/cmTC_eb9e9.dir/feature_tests.c.o -o cmTC_eb9e9
make[1]: Leaving directory '/tmp/leveldb/CMakeFiles/CMakeTmp'

Cannot copy output executable
''
to destination specified by COPY_FILE:
'/tmp/leveldb/CMakeFiles/feature_tests.bin'
Unable to find the executable at any of:
/tmp/leveldb/CMakeFiles/CMakeTmp/cmTC_eb9e9
/tmp/leveldb/CMakeFiles/CMakeTmp/Debug/cmTC_eb9e9
/tmp/leveldb/CMakeFiles/CMakeTmp/Development/cmTC_eb9e9

Detecting CXX compiler ABI info failed to compile with the following output:
Change Dir: /tmp/leveldb/CMakeFiles/CMakeTmp

Run Build Command:"/usr/bin/make" "cmTC_c2c8d/fast"
/usr/bin/make -f CMakeFiles/cmTC_c2c8d.dir/build.make CMakeFiles/cmTC_c2c8d.dir/build
make[1]: Entering directory '/tmp/leveldb/CMakeFiles/CMakeTmp'
Building CXX object CMakeFiles/cmTC_c2c8d.dir/CMakeCXXCompilerABI.cpp.o
/home/catror/.vim/plugged/YCM-Generator/fake-toolchain/Unix/clang++ -o CMakeFiles/cmTC_c2c8d.dir/CMakeCXXCompilerABI.cpp.o -c /usr/local/share/cmake-3.12/Modules/CMakeCXXCompilerABI.cpp
Linking CXX executable cmTC_c2c8d
/usr/local/bin/cmake -E cmake_link_script CMakeFiles/cmTC_c2c8d.dir/link.txt --verbose=1
/home/catror/.vim/plugged/YCM-Generator/fake-toolchain/Unix/clang++ -v CMakeFiles/cmTC_c2c8d.dir/CMakeCXXCompilerABI.cpp.o -o cmTC_c2c8d
clang version 7.0.0 (tags/RELEASE_700/final)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /usr/local/bin
Found candidate GCC installation: /usr/lib/gcc/i686-linux-gnu/5
Found candidate GCC installation: /usr/lib/gcc/i686-linux-gnu/5.4.0
Found candidate GCC installation: /usr/lib/gcc/i686-linux-gnu/6
Found candidate GCC installation: /usr/lib/gcc/i686-linux-gnu/6.0.0
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/5
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/5.4.0
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/6
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/6.0.0
Selected GCC installation: /usr/lib/gcc/x86_64-linux-gnu/5.4.0
Candidate multilib: .;@m64
Selected multilib: .;@m64
"/home/catror/.vim/plugged/YCM-Generator/fake-toolchain/Unix/ld" -z relro --hash-style=gnu --eh-frame-hdr -m elf_x86_64 -dynamic-linker /lib64/ld-linux-x86-64.so.2 -o cmTC_c2c8d /usr/lib/gcc/x86_64-linux-gnu/5.4.0/../../../x86_64-linux-gnu/crt1.o /usr/lib/gcc/x86_64-linux-gnu/5.4.0/../../../x86_64-linux-gnu/crti.o /usr/lib/gcc/x86_64-linux-gnu/5.4.0/crtbegin.o -L/usr/lib/gcc/x86_64-linux-gnu/5.4.0 -L/usr/lib/gcc/x86_64-linux-gnu/5.4.0/../../../x86_64-linux-gnu -L/lib/x86_64-linux-gnu -L/lib/../lib64 -L/usr/lib/x86_64-linux-gnu -L/usr/lib/gcc/x86_64-linux-gnu/5.4.0/../../.. -L/usr/local/bin/../lib -L/lib -L/usr/lib CMakeFiles/cmTC_c2c8d.dir/CMakeCXXCompilerABI.cpp.o -lstdc++ -lm -lgcc_s -lgcc -lc -lgcc_s -lgcc /usr/lib/gcc/x86_64-linux-gnu/5.4.0/crtend.o /usr/lib/gcc/x86_64-linux-gnu/5.4.0/../../../x86_64-linux-gnu/crtn.o
make[1]: Leaving directory '/tmp/leveldb/CMakeFiles/CMakeTmp'

Cannot copy output executable
''
to destination specified by COPY_FILE:
'/tmp/leveldb/CMakeFiles/3.12.4/CMakeDetermineCompilerABI_CXX.bin'
Unable to find the executable at any of:
/tmp/leveldb/CMakeFiles/CMakeTmp/cmTC_c2c8d
/tmp/leveldb/CMakeFiles/CMakeTmp/Debug/cmTC_c2c8d
/tmp/leveldb/CMakeFiles/CMakeTmp/Development/cmTC_c2c8d

Detecting CXX [-std=c++2a] compiler features failed to compile with the following output:
Change Dir: /tmp/leveldb/CMakeFiles/CMakeTmp

Run Build Command:"/usr/bin/make" "cmTC_94f2a/fast"
/usr/bin/make -f CMakeFiles/cmTC_94f2a.dir/build.make CMakeFiles/cmTC_94f2a.dir/build
make[1]: Entering directory '/tmp/leveldb/CMakeFiles/CMakeTmp'
Building CXX object CMakeFiles/cmTC_94f2a.dir/feature_tests.cxx.o
/home/catror/.vim/plugged/YCM-Generator/fake-toolchain/Unix/clang++ -std=c++2a -o CMakeFiles/cmTC_94f2a.dir/feature_tests.cxx.o -c /tmp/leveldb/CMakeFiles/feature_tests.cxx
Linking CXX executable cmTC_94f2a
/usr/local/bin/cmake -E cmake_link_script CMakeFiles/cmTC_94f2a.dir/link.txt --verbose=1
/home/catror/.vim/plugged/YCM-Generator/fake-toolchain/Unix/clang++ CMakeFiles/cmTC_94f2a.dir/feature_tests.cxx.o -o cmTC_94f2a
make[1]: Leaving directory '/tmp/leveldb/CMakeFiles/CMakeTmp'

Cannot copy output executable
''
to destination specified by COPY_FILE:
'/tmp/leveldb/CMakeFiles/feature_tests.bin'
Unable to find the executable at any of:
/tmp/leveldb/CMakeFiles/CMakeTmp/cmTC_94f2a
/tmp/leveldb/CMakeFiles/CMakeTmp/Debug/cmTC_94f2a
/tmp/leveldb/CMakeFiles/CMakeTmp/Development/cmTC_94f2a