Are you building it on Windows? MPICH 3 series does not support Windows. Try Microsoft MPI : https://docs.microsoft.com/en-us/message-passing-interface/microsoft-mpi -- Hui Zhou From: Mbaabu Brian via discuss <[email protected]> Reply-To: "[email protected]" <[email protected]> Date: Saturday, April 4, 2020 at 8:42 AM To: "[email protected]" <[email protected]> Cc: Mbaabu Brian <[email protected]> Subject: [mpich-discuss] MPICH INSTALLATION ERRORS Hello, My installation produced such errors as are documented in the attached log files. Please help me resolve them.