我试图在我的Mac上安装mpi（运行Yosemite），然后运行以下内容：
brew update
brew install open-mpi
一切似乎都没问题，但当我尝试编译我的文件mpi.cpp时，我收到了：
Undefined symbols for architecture x86_64:
"_MPI_Allgatherv", referenced from:
_main in mpi.o
"_MPI_Comm_rank", referenced from:
_main in mpi.o
"_MPI_Comm_size", referenced from:
_main in mpi.o
"_MPI_Finalize", referenced from:
_main in mpi.o
"_MPI_Init", referenced from:
_main in mpi.o
"_MPI_Reduce", referenced from:
_main in mpi.o
"_MPI_Scatterv", referenced from:
_main in mpi.o
"_MPI_Type_commit", referenced from:
_main in mpi.o
"_MPI_Type_contiguous", referenced from:
_main in mpi.o
"_ompi_mpi_comm_world", referenced from:
_main in mpi.o
"_ompi_mpi_double", referenced from:
_main in mpi.o
"_ompi_mpi_int", referenced from:
_main in mpi.o
"_ompi_mpi_op_min", referenced from:
_main in mpi.o
"_ompi_mpi_op_sum", referenced from:
_main in mpi.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make: *** [mpi] Error 1
我不确定该怎么做。还有一个额外的步骤吗？