CODEWITHSUNDEEP
cmakempiubuntu-20.04
Ronan
Ronan

Reputation: 468

How do I resolve the CMake error "Could not find MPI"

I am trying to run a CMakeLists.txt file on a (48h) fresh ubuntu 20.04.3 install. I keep getting the following error when running cmake .

-- Could NOT find MPI_CXX (missing: MPI_CXX_WORKS)
CMake Error at /usr/share/cmake-3.16/Modules/FindPackageHandleStandardArgs.cmake:146 (message):
  Could NOT find MPI (missing: MPI_CXX_FOUND) (found version "3.1")
Call Stack (most recent call first):
  /usr/share/cmake-3.16/Modules/FindPackageHandleStandardArgs.cmake:393 (_FPHSA_FAILURE_MESSAGE)
  /usr/share/cmake-3.16/Modules/FindMPI.cmake:1688 (find_package_handle_standard_args)
  CMakeLists.txt:16 (find_package)


-- Configuring incomplete, errors occurred!

As far as I can tell the relevant lines in CMakeLists.txt are the following:

# check MPI package...
find_package(MPI REQUIRED)
set(CMAKE_CXX_COMPILER mpicxx)
include_directories(${MPI_INCLUDE_DIR})

I have tried to resolve this by installing through apt mpich. Although the install works and running mpich --version returns (below) the error persists.

gcc (Ubuntu 9.3.0-17ubuntu1~20.04) 9.3.0
Copyright (C) 2019 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

cmake --version returns 3.16.3

I have made restart(s) since installing each package. I have also added to my ~/.bashrc

export PATH=$PATH:/usr/bin/mpicc
export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/bin/mpicc

which also seems to have done nothing (this after a restart again).

If relevant, I have also installed through apt cmake, libboost-all-dev, cuda-10-1, libcudnn7, libblas-dev, liblapack-dev, mpi

I would appreciate any help in the matter.

Upvotes: 6

Views: 29945

Answers (3)

mafu
mafu

Reputation: 32700

Another solution that worked for me: Clear the CMake caches.

Upvotes: 0

Chang
Chang

Reputation: 71

Setting CMAKE_PREFIX_PATH did not solve my problem. I got it solved by using the variable CMAKE_C_COMPILER and CMAKE_CXX_COMPILE mentioned in this issue: https://github.com/3dem/relion/issues/702

As such, my cmake command now looks like:

cmake -DCMAKE_C_COMPILER=/home/user/opt/openmpi/bin/mpicc -DCMAKE_CXX_COMPILER=/home/user/opt/openmpi/bin/mpicxx .

, where /home/user/opt/openmpi/bin is the location of your MPI binaries.

Upvotes: 3

Ivan Vorobyev
Ivan Vorobyev

Reputation: 176

Use CMAKE_PREFIX_PATH variable to set search path. Best practice is set that variable in command line interface:

mkdir build
cd build
cmake -G "Unix Makefiles" .. -DCMAKE_PREFIX_PATH=path_to_mpi_lib

Anyway you can set the following variables for locating MPI before find_package command (description from FindMPI.cmake):

``MPIEXEC_EXECUTABLE``
  Manually specify the location of ``mpiexec``.
``MPI_HOME``
  Specify the base directory of the MPI installation.
``ENV{MPI_HOME}``
  Environment variable to specify the base directory of the MPI installation.
``ENV{I_MPI_ROOT}``
  Environment variable to specify the base directory of the MPI installation.

Upvotes: 7

Related Questions