Failed Installing xgboost==0.6a2 on Mac Mojave

I have tried all possible solution I can find on web to install xgboost==0.6a2

I have MacOS Mojave 10.14.4

I am trying in virtualenv having python 3.6

Here is result of pip command

pip install xgboost==0.6a2
Collecting xgboost==0.6a2
  Using cached https://files.pythonhosted.org/packages/34/85/456a1a8c762f646671043e446a59efbce02b5f408f522c4ef8793e860c5e/xgboost-0.6a2.tar.gz
    ERROR: Complete output from command python setup.py egg_info:
    ERROR: rm -f -rf build build_plugin lib bin *~ */*~ */*/*~ */*/*/*~ */*.o */*/*.o */*/*/*.o xgboost
    clang-omp++ -std=c++0x -Wall -O3 -msse2  -Wno-unknown-pragmas -funroll-loops -Iinclude   -Idmlc-core/include -Irabit/include -fPIC -fopenmp -MM -MT build/learner.o src/learner.cc >build/learner.d
    /bin/sh: clang-omp++: command not found
    make: *** [build/learner.o] Error 127
    make: *** Waiting for unfinished jobs....
    clang-omp++ -std=c++0x -Wall -O3 -msse2  -Wno-unknown-pragmas -funroll-loops -Iinclude   -Idmlc-core/include -Irabit/include -fPIC -fopenmp -MM -MT build/logging.o src/logging.cc >build/logging.d
    /bin/sh: clang-omp++: command not found
    make: *** [build/logging.o] Error 127
    -----------------------------
    Building multi-thread xgboost failed
    Start to build single-thread xgboost
    rm -f -rf build build_plugin lib bin *~ */*~ */*/*~ */*/*/*~ */*.o */*/*.o */*/*/*.o xgboost
    clang-omp++ -std=c++0x -Wall -O3 -msse2  -Wno-unknown-pragmas -funroll-loops -Iinclude   -Idmlc-core/include -Irabit/include -fPIC -fopenmp -MM -MT build/learner.o src/learner.cc >build/learner.d
    /bin/sh: clang-omp++: command not found
    make: *** [build/learner.o] Error 127
    make: *** Waiting for unfinished jobs....
    clang-omp++ -std=c++0x -Wall -O3 -msse2  -Wno-unknown-pragmas -funroll-loops -Iinclude   -Idmlc-core/include -Irabit/include -fPIC -fopenmp -MM -MT build/logging.o src/logging.cc >build/logging.d
    /bin/sh: clang-omp++: command not found
    make: *** [build/logging.o] Error 127
    Successfully build single-thread xgboost
    If you want multi-threaded version
    See additional instructions in doc/build.md
    Traceback (most recent call last):
      File "<string>", line 1, in <module>
      File "/private/var/folders/8s/jbryfvkn68jg4d2p2mncgqqw0000gq/T/pip-install-bp2gsdf9/xgboost/setup.py", line 29, in <module>
        LIB_PATH = libpath['find_lib_path']()
      File "/private/var/folders/8s/jbryfvkn68jg4d2p2mncgqqw0000gq/T/pip-install-bp2gsdf9/xgboost/xgboost/libpath.py", line 45, in find_lib_path
        'List of candidates:\n' + ('\n'.join(dll_path)))
    XGBoostLibraryNotFound: Cannot find XGBoost Libarary in the candicate path, did you install compilers and run build.sh in root path?
    List of candidates:
    /private/var/folders/8s/jbryfvkn68jg4d2p2mncgqqw0000gq/T/pip-install-bp2gsdf9/xgboost/xgboost/libxgboost.so
    /private/var/folders/8s/jbryfvkn68jg4d2p2mncgqqw0000gq/T/pip-install-bp2gsdf9/xgboost/xgboost/../../lib/libxgboost.so
    /private/var/folders/8s/jbryfvkn68jg4d2p2mncgqqw0000gq/T/pip-install-bp2gsdf9/xgboost/xgboost/./lib/libxgboost.so
    ----------------------------------------
ERROR: Command "python setup.py egg_info" failed with error code 1 in /private/var/folders/8s/jbryfvkn68jg4d2p2mncgqqw0000gq/T/pip-install-bp2gsdf9/xgboost/

I downloaded xgboost and tried to install from source

python setup.py install
rm -f -rf build build_plugin lib bin *~ */*~ */*/*~ */*/*/*~ */*.o */*/*.o */*/*/*.o xgboost
clang-omp++ -std=c++0x -Wall -O3 -msse2  -Wno-unknown-pragmas -funroll-loops -Iinclude   -Idmlc-core/include -Irabit/include -fPIC -fopenmp -MM -MT build/learner.o src/learner.cc >build/learner.d
/bin/sh: clang-omp++: command not found
make: *** [build/learner.o] Error 127
make: *** Waiting for unfinished jobs....
clang-omp++ -std=c++0x -Wall -O3 -msse2  -Wno-unknown-pragmas -funroll-loops -Iinclude   -Idmlc-core/include -Irabit/include -fPIC -fopenmp -MM -MT build/logging.o src/logging.cc >build/logging.d
/bin/sh: clang-omp++: command not found
make: *** [build/logging.o] Error 127
-----------------------------
Building multi-thread xgboost failed
Start to build single-thread xgboost
rm -f -rf build build_plugin lib bin *~ */*~ */*/*~ */*/*/*~ */*.o */*/*.o */*/*/*.o xgboost
clang-omp++ -std=c++0x -Wall -O3 -msse2  -Wno-unknown-pragmas -funroll-loops -Iinclude   -Idmlc-core/include -Irabit/include -fPIC -fopenmp -MM -MT build/learner.o src/learner.cc >build/learner.d
/bin/sh: clang-omp++: command not found
make: *** [build/learner.o] Error 127
make: *** Waiting for unfinished jobs....
clang-omp++ -std=c++0x -Wall -O3 -msse2  -Wno-unknown-pragmas -funroll-loops -Iinclude   -Idmlc-core/include -Irabit/include -fPIC -fopenmp -MM -MT build/logging.o src/logging.cc >build/logging.d
/bin/sh: clang-omp++: command not found
make: *** [build/logging.o] Error 127
Successfully build single-thread xgboost
If you want multi-threaded version
See additional instructions in doc/build.md
Traceback (most recent call last):
  File "setup.py", line 29, in <module>
    LIB_PATH = libpath['find_lib_path']()
  File "xgboost/libpath.py", line 45, in find_lib_path
    'List of candidates:\n' + ('\n'.join(dll_path)))
XGBoostLibraryNotFound: Cannot find XGBoost Libarary in the candicate path, did you install compilers and run build.sh in root path?
List of candidates:
/Users/karim/Documents/software/xgboost-0.6a2/xgboost/libxgboost.so
/Users/karim/Documents/software/xgboost-0.6a2/xgboost/../../lib/libxgboost.so
/Users/karim/Documents/software/xgboost-0.6a2/xgboost/./lib/libxgboost.so

I also tried to install gcc5 by

brew install gcc@5

Which gives

Error: gcc@5 5.5.0_2 is already installed

When I type gcc -v it gives

Configured with: --prefix=/Library/Developer/CommandLineTools/usr
–with-gxx-include-dir=/Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/include/c++/4.2.1
Apple LLVM version 10.0.1 (clang-1001.0.46.4) Target:
x86_64-apple-darwin18.5.0 Thread model: posix InstalledDir:
/Library/Developer/CommandLineTools/usr/bin

Are there any specific steps to be followed on Mac to configure it?

Any help highly appreciated.

Try setting the environment variable CXX=g++-5.

Also, I suggest that you use a more recent version of XGBoost. All existing docs assume that you are using 0.72 or higher.