installation error on windows: omp.h not found

[bishwarup307]

I am trying to install the xgboost python package on windows 8 (64 bit) following the instructions given here: http://stackoverflow.com/questions/33749735/how-to-install-xgboost-package-in-python-windows-platform/35480673#35480673 and http://xgboost.readthedocs.org/en/latest/build.html#building-on-windows.

After I run the command: make -j4, i get the following error:
dmlc-core/include/dmlc/omp.h:9:17: fatal error: omp.h: No such file or directory
I am executing the commands on a Cygwin shell. Any suggestions?

[FACE1E55]

@bishwarup307 I'm not sure if it works fine, but here is somethng to try.
I had similar issue and it disappeared after I did the following:

• delete dmlc-core directory
• git clone https://github.com/dmlc/dmlc-core
• cd dmlc-core
• make, or mingw32-make, or anything
  Then continue with installing xgboost.
  Hope it works for you.

[Diyago]

I have the same error as @bishwarup307 . Tried @FACE1E55 solution, but I get such error:

$ cd dmlc-core

sbt-ashrapov-ir@IDF3-9040043 MINGW32 ~/xgboost/dmlc-core ((1db0792...))
$ mingw32-make
g++ -c -O3 -Wall -msse2  -Wno-unknown-pragmas -Iinclude  -std=c++0x -fopenmp -fPIC -DDMLC_USE_HDFS=0 -DDMLC_USE_S3=0 -DDMLC_USE_AZURE=0 -o line_split.o src/io/line_split.cc
src/io/line_split.cc:1:0: warning: -fPIC ignored for target (all code is position independent)
 // Copyright by Contributors
 ^
In file included from c:\users\\minigw\lib\gcc\mingw32\4.9.3\include\c++\cmath:44:0,
                 from c:\users\\minigw\lib\gcc\mingw32\4.9.3\include\c++\random:38,
                 from c:\users\\minigw\lib\gcc\mingw32\4.9.3\include\c++\bits\stl_algo.h:66,
                 from c:\users\\minigw\lib\gcc\mingw32\4.9.3\include\c++\algorithm:62,
                 from src/io/line_split.cc:4:
c:\users\\minigw\include\math.h: In function 'float hypotf(float, float)':
c:\users\\minigw\include\math.h:635:30: error: '_hypot' was not declared in this scope
 { return (float)(_hypot (x, y)); }
                              ^
Makefile:75: recipe for target 'line_split.o' failed
mingw32-make: *** [line_split.o] Error 1

[luthfianto]

Experienced the same error with gcc-6-win-64 and make (not mingw32-make)

λ make -j4
g++ -m64 -std=c++0x -Wall -O3 -msse2  -Wno-unknown-pragmas -funroll-loops -Iinclude -DDMLC_ENABLE_STD_THREAD=0  -Idmlc-core/include -Irabit/include -fopenmp -MM -MT build/learner.o src/learner.cc >build/learner.d
g++ -m64 -c -std=c++0x -Wall -O3 -msse2  -Wno-unknown-pragmas -funroll-loops -Iinclude -DDMLC_ENABLE_STD_THREAD=0  -Idmlc-core/include -Irabit/include -fopenmp -c src/learner.cc -o build/learner.o
In file included from include/xgboost/./base.h:10:0,
                 from include/xgboost/logging.h:13,
                 from src/learner.cc:7:
dmlc-core/include/dmlc/omp.h:9:17: fatal error: omp.h: No such file or directory
 #include <omp.h>
                 ^
compilation terminated.
make: *** [Makefile:99: build/learner.o] Error 1

Looks like this compiler doesn't compiled with OpenMP. I'll just switch to TDM-GCC even it's only GCC 5

[luthfianto]

Well, ran into another error with TDM-GCC

λ make -j4
g++ -m64 -std=c++0x -Wall -O3 -msse2  -Wno-unknown-pragmas -funroll-loops -Iinclude -DDMLC_ENABLE_STD_THREAD=0  -Idmlc-core/include -Irabit/include -fopenmp -MM -MT build/c_api/c_api_error.o src/c_api/c_api_error.cc >build/c_api/c_api_error.d
g++ -m64 -c -std=c++0x -Wall -O3 -msse2  -Wno-unknown-pragmas -funroll-loops -Iinclude -DDMLC_ENABLE_STD_THREAD=0  -Idmlc-core/include -Irabit/include -fopenmp -c src/c_api/c_api_error.cc -o build/c_api/c_api_error.o
In file included from C:/TDM-GCC-64/x86_64-w64-mingw32/include/locale.h:12:0,
                 from C:/TDM-GCC-64/lib/gcc/x86_64-w64-mingw32/5.1.0/include/c++/clocale:42,
                 from C:/TDM-GCC-64/lib/gcc/x86_64-w64-mingw32/5.1.0/include/c++/x86_64-w64-mingw32/bits/c++locale.h:41,
                 from C:/TDM-GCC-64/lib/gcc/x86_64-w64-mingw32/5.1.0/include/c++/bits/localefwd.h:40,
                 from C:/TDM-GCC-64/lib/gcc/x86_64-w64-mingw32/5.1.0/include/c++/string:43,
                 from dmlc-core/include/dmlc/base.h:154,
                 from src/c_api/./c_api_error.h:9,
                 from src/c_api/c_api_error.cc:6:
C:/TDM-GCC-64/x86_64-w64-mingw32/include/stdio.h:450:83: error: 'FILE* std::fopen(const char*, const char*)' should have been declared inside 'std'
   FILE *fopen64(const char * __restrict__ filename,const char * __restrict__  mode);
                                                                                   ^
C:/TDM-GCC-64/x86_64-w64-mingw32/include/stdio.h:450:83: error: 'FILE* std::fopen(const char*, const char*)' conflicts with a previous declaration
C:/TDM-GCC-64/x86_64-w64-mingw32/include/stdio.h:449:17: note: previous declaration 'FILE* fopen(const char*, const char*)'
   FILE *__cdecl fopen(const char * __restrict__ _Filename,const char * __restrict__ _Mode) __MINGW_ATTRIB_DEPRECATED_SEC_WARN;
                 ^
Makefile:97: recipe for target 'build/c_api/c_api_error.o' failed
mingw32-make: *** [build/c_api/c_api_error.o] Error 1

Months ago it was just fine installing with TDM-GCC. Where does this error looks from?

[luthfianto]

Now I installed xgboost just fine

The takeaway:

• If you encountered an error with omp/libgomp. Make sure you installed a compiler with OpenMP/libgomp support. (TDM-GCC with OpenMP option ticked/enabled at installation works fine).
• If you encountered an error like mine above, actually you have no problem with your compiler anymore. Please refer to Should I MAKE dmlc-core first? Or directly MAKE xgboost? Window7 + mingw64 #1299 (comment) because there's some issues with MinGW inconsistencies or whatever