The MPI test test_mpi for CXX in mode normal failed to compile with the following output: Change Dir: /home/pbrault/lammps-8Apr21/build/CMakeFiles/CMakeTmp Run Build Command(s):/usr/bin/gmake cmTC_d6cdc/fast && /usr/bin/gmake -f CMakeFiles/cmTC_d6cdc.dir/build.make CMakeFiles/cmTC_d6cdc.dir/build gmake[1]: Entering directory '/home/pbrault/lammps-8Apr21/build/CMakeFiles/CMakeTmp' Building CXX object CMakeFiles/cmTC_d6cdc.dir/test_mpi.cpp.o /usr/bin/c++ -std=c++11 -o CMakeFiles/cmTC_d6cdc.dir/test_mpi.cpp.o -c /home/pbrault/lammps-8Apr21/build/CMakeFiles/FindMPI/test_mpi.cpp /home/pbrault/lammps-8Apr21/build/CMakeFiles/FindMPI/test_mpi.cpp:1:10: fatal error: mpi.h: No such file or directory #include ^~~~~~~ compilation terminated. gmake[1]: *** [CMakeFiles/cmTC_d6cdc.dir/build.make:83: CMakeFiles/cmTC_d6cdc.dir/test_mpi.cpp.o] Error 1 gmake[1]: Leaving directory '/home/pbrault/lammps-8Apr21/build/CMakeFiles/CMakeTmp' gmake: *** [Makefile:138: cmTC_d6cdc/fast] Error 2 Looking for a Fortran compiler failed with the following output: -- The Fortran compiler identification is unknown CMake Error at CMakeLists.txt:2 (project): No CMAKE_Fortran_COMPILER could be found. Tell CMake where to find the compiler by setting either the environment variable "FC" or the CMake cache entry CMAKE_Fortran_COMPILER to the full path to the compiler, or to the compiler name if it is in the PATH. -- Configuring incomplete, errors occurred! See also "/home/pbrault/lammps-8Apr21/build/CMakeFiles/CheckFortran/CMakeFiles/CMakeOutput.log". See also "/home/pbrault/lammps-8Apr21/build/CMakeFiles/CheckFortran/CMakeFiles/CMakeError.log".