Recently I switched to gcc-6 in my OS X, and faced to VARIOUS of disasterS. One of them is the gcc compile cannot find header "stdlib.h"
For detail, we can find error message as follow:
In file included from /usr/local/Cellar/gcc/6.2.0/include/c++/6.2.0/ext/string_conversions.h:41:0,
from /usr/local/Cellar/gcc/6.2.0/include/c++/6.2.0/bits/basic_string.h:5402,
from /usr/local/Cellar/gcc/6.2.0/include/c++/6.2.0/string:52,
from /Users/yu/.local/src/xgboost/dmlc-core/include/dmlc/base.h:171,
from /Users/yu/.local/src/xgboost/dmlc-core/src/recordio.cc:3:
/usr/local/Cellar/gcc/6.2.0/include/c++/6.2.0/cstdlib:75:25: fatal error: stdlib.h: No such file or directory
#include_next <stdlib.h>
^
compilation terminated.
Thousands of similar questions can be found in google and most of them are stupid s**t. After hours' check, this follow up gives me the answer.
Afaik new GCC 6 trips if you manually pass /usr/include in the wrong order. What happens if you remove that obvious CPLUS_INCLUDE_PATH, and check the makefile/configure script for any -I /usr/include and subsequently remove them? Not on my arch would test that myself otherwise.
This problem is from my environment settings. At first, my environment parameter CPLUS_INCLUDE_PATH written as follow:
export CPLUS_INCLUDE_PATH=$CPLUS_INCLUDE_PATH:/usr/include:/usr/local/include:$HOME/.local/include:/some/other/paths
This sequence is incorrect, because we can find stdlib.h in /usr/include , but that stdlib.h is not expected by gcc-6, and an fatal error comes.
To fix this problem, a fix may as follow:
export CPLUS_INCLUDE_PATH=/usr/local/Cellar/gcc/6.2.0/include/c++/6.2.0:/usr/include:/usr/local/include:$HOME/.local/include:$CPLUS_INCLUDE_PATH
And finally, it works.
PS:
How to install gcc-6 in OS X?
We shall install homebrew first, and then type:
brew install gcc --without-multilib
brew is the de facto standard of yum/dnf/apt-get on OS X. You can use parameter "--without-multilib" to obtain the support OpenMP, and it will take you quite a while (~30 min) to compile the whole gcc. You can check here and here for more details.
How to change default C/C++ compile?
You can edit your ~/.bash_profile or ~/.bashrc, create one if not exists, and then append lines as follow:
CC=/usr/local/bin/gcc-6 CXX=/usr/local/bin/g++-6
Your cmake or most of other makefiles will detect these environment parameters and use them as default C/C++ compile
