[rajibroy]

I am facing an error while compiling OpenFOAM-dev from sources in my Ubuntu 14:04 machine while following the instructions on OpenFOAMwiki page. I am installing it with "Debug" option and GCC compilers. I am stuck in step 12.2 and the system info & error message is as follows:

Sys info:

 rroy@Precision:~/OpenFOAM/OpenFOAM-dev-debug$ uname -a
Linux Precision 4.4.0-78-generic #99~14.04.2-Ubuntu SMP Thu Apr 27 18:49:46 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux

Error message:

 wclean ptscotchDecomp
wmake  ptscotchDecomp
wmake ptscotchDecomp
wmakeLnInclude: linking include files to ./lnInclude
Making dependency list for source file ptscotchDecomp.C
g++ -std=c++11 -m64 -Dlinux64 -DWM_ARCH_OPTION=64 -DWM_DP -DWM_LABEL_SIZE=32 -Wall -Wextra -Wold-style-cast -Wnon-virtual-dtor -Wno-unused-parameter -Wno-invalid-offsetof -O0 -fdefault-inline -ggdb3 -DFULLDEBUG -DNoRepository -ftemplate-depth-100 -DOMPI_SKIP_MPICXX -I/usr/local/include -pthread -I/home/rroy/OpenFOAM/ThirdParty-dev-debug/platforms/linux64GccDPInt32/scotch_6.0.3/include/openmpi-system -I/home/rroy/OpenFOAM/ThirdParty-dev-debug/platforms/linux64GccDPInt32/scotch_6.0.3/include -I/usr/include/scotch -I../decompositionMethods/lnInclude -IlnInclude -I. -I/home/rroy/OpenFOAM/OpenFOAM-dev-debug/src/OpenFOAM/lnInclude -I/home/rroy/OpenFOAM/OpenFOAM-dev-debug/src/OSspecific/POSIX/lnInclude   -fPIC -c ptscotchDecomp.C -o /home/rroy/OpenFOAM/OpenFOAM-dev-debug/platforms/linux64GccDPInt32DebugSYSTEMOPENMPI/src/parallel/decompose/ptscotchDecomp/ptscotchDecomp.o
In file included from /usr/local/include/mpi.h:2231:0,
                 from ptscotchDecomp.C:36:
/usr/local/include/mpicxx.h:2737:34: error: declaration of C function ‘void MPI::Init(int&, char**&)’ conflicts with
 extern void Init(int &, char **& );
                                  ^
/usr/local/include/mpicxx.h:2736:13: error: previous declaration ‘void MPI::Init()’ here
 extern void Init(void);
             ^
/usr/local/include/mpicxx.h:2739:45: error: declaration of C function ‘int MPI::Init_thread(int&, char**&, int)’ conflicts with
 extern int Init_thread(int &, char **&, int );
                                             ^
/usr/local/include/mpicxx.h:2738:12: error: previous declaration ‘int MPI::Init_thread(int)’ here
 extern int Init_thread(int);
            ^
make: *** [/home/rroy/OpenFOAM/OpenFOAM-dev-debug/platforms/linux64GccDPInt32DebugSYSTEMOPENMPI/src/parallel/decompose/ptscotchDecomp/ptscotchDecomp.o] Error 1

Could you please advise in this regard? Thanks in advance.

[wyldckat]

Quick answer: The output indicates that you are not using the default Open-MPI system installation, given that it's using the file "/usr/local/include/mpi.h".

Which specific MPI version are you using? It doesn't seem to be compatible or perhaps you need to adjust the OpenFOAM environment variable "WM_MPLIB" to the correct setting.

For getting the specific version of Open-MPI that you are using, try running this command:

mpirun --version
which mpirun

to see the version and to see if the path also points to "/usr/local/bin".