Hi everyone, I have installed firedrake on my university's HPC machine, and whenever i attempt to run any Firedrake program, I get this error: -------------------------------------------------------------------------- An MPI process has executed an operation involving a call to the "fork()" system call to create a child process. Open MPI is currently operating in a condition that could result in memory corruption or other system errors; your MPI job may hang, crash, or produce silent data corruption. The use of fork() (or system() or other calls that create child processes) is strongly discouraged. The process that invoked fork was: Local host: compute-0-0 (PID 28214) MPI_COMM_WORLD rank: 0 If you are *absolutely sure* that your application will successfully and correctly survive a call to fork(), you may disable this warning by setting the mpi_warn_on_fork MCA parameter to 0. -------------------------------------------------------------------------- Why is this happening? Program seems fine when I only use a few processes but when I use two or more compute nodes, my program hangs. I'll do my best to explain how I built firedrake: 1) Our system has openmpi-1.8.3 and gcc-4.9.2 available. so those are the only modules I have loaded, everything else was downloaded. 2) I built Python 2.7.10 from source and installed it in ${HOME}/.local 3) pip was obtained via python get-pip.py 4) PETSc was installed --with-cc=mpmicc, --with-cxx=mpicxx, and has all the necessary external packages 5) petsc4py was installed via git clone ... and set up with python setup.py build/install 6) PyOP2 was built with python setup.py build_ext --inplace 7) Firedrake was built via make and everything else was installed via 'pip install <package>'. I had to manually install swig and pcre. Any ideas what this may be? And/or how I can circumvent this issue? Thanks, Justin