Today I tried to install dlib on my CentOS 6.7 server using this command:
pip install dlib
There is an error:
Unsupported compiler — pybind11 requires C++11 support!
To fix this issue, we need to replace the C++ compiler in /usr/bin by newer version.
So we have to install newer gcc version and replace the c++ compiler with the newer one.
Firstly, we have to install some additional required packages:
sudo yum install svn texinfo-tex flex zip libgcc.i686 glibc-devel.i686
Then find gcc available versions:
svn ls svn://gcc.gnu.org/svn/gcc/tags | grep gcc | grep release
I found that gcc 5.5.0 is okay to fix the error above. So I install gcc 5.5.0
svn co svn://gcc.gnu.org/svn/gcc/tags/gcc_5_1_0_release/
Get source of additional prerequisites:
cd gcc_5_1_0_release/ ./contrib/download_prerequisites
Building gcc could eat much memory. If your server has less than 2GB RAM, you should create swap file:
SWAP=/tmp/swap dd if=/dev/zero of=$SWAP bs=1M count=500 mkswap $SWAP sudo swapon $SWAP
Now build gcc:
mkdir build cd build ../configure make
Building gcc can take 1 hour. So we have to wait now.
After building successfully, we can install it
make install
Now the new c++ compiler is installed in /usr/local/bin/ folder. We need to replace the current c++ compiler with this newer one.
We backup the current compiler first:
mv /usr/bin/cc /usr/bin/cc4.4.7 mv /usr/bin/c++ /usr/bin/c++4.4.7
Then create symbolic link to the newer version
ln -s /usr/local/bin/cc /usr/bin/cc ln -s /usr/local/bin/c++ /usr/bin/c++
Now I can install dlib without the error above:
pip install dlib
After installing, there is an error when importing dlib into python
ImportError: /usr/lib64/libstdc++.so.6: version `GLIBCXX_3.4.20′ not found (required by /usr/local/lib/python2.7/site-packages/dlib/dlib.so
To fix it, we replace the lib in /usr/lib64 with the newer one that we have just built:
mv /usr/lib64/libstdc++.so.6 /usr/lib64/libstdc++.so.6.old ln -s /usr/local/lib64/libstdc++.so.6 /usr/lib64/libstdc++.so.6