When trying to install MPICH from the apt repository on Ubuntu 24.04 and then installing mpi4py with pip, I get a non-functional installation of mpi4py. It does not happen if I use openmpi, or downgrade to Ubuntu 22.04. It has been tested with the same MPICH on other systems (See: https://urldefense.us/v3/__https://github.com/mpi4py/mpi4py/issues/547__;!!G... ) for where it has been tested, leading one to believe that something is wrong with the ubuntu build. Minimal reproducible dockerfile: ``` FROM ubuntu:24.04 ARG MPI="mpich" ENV OPENBLAS_NUM_THREADS=1 \ OPENBLAS_VERBOSE=0 ENV DEB_PYTHON_INSTALL_LAYOUT=deb_system ENV DEBIAN_FRONTEND=noninteractive WORKDIR /tmp RUN apt-get -qq update && \ apt-get -yq upgrade && \ apt-get -y install \ lib${MPI}-dev \ python3-dev \ python3-pip \ python3-setuptools \ python3-venv && \ apt-get clean && \ rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/* ENV VIRTUAL_ENV=/test-env ENV PATH=/${VIRTUAL_ENV}/bin:$PATH RUN python3 -m venv ${VIRTUAL_ENV} # Install Python packages (via pip) RUN python3 -m pip install --no-cache-dir mpi4py -v ENV OMPI_ALLOW_RUN_AS_ROOT=1 \ OMPI_ALLOW_RUN_AS_ROOT_CONFIRM=1 CMD ["mpiexec", "-v", "--np", "2", "python3", "-c", "from mpi4py import MPI; print(f'{MPI.COMM_WORLD.rank}/{MPI.COMM_WORLD.size}')"] ``` with the output ``` host: 6a2e05040a65 [mpiexec@6a2e05040a65] Timeout set to -1 (-1 means infinite) ================================================================================================== mpiexec options: ---------------- Base path: /usr/bin/ Launcher: (null) Debug level: 1 Enable X: -1 Global environment: ------------------- PATH=//test-env/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin HOSTNAME=6a2e05040a65 TERM=xterm OPENBLAS_NUM_THREADS=1 OPENBLAS_VERBOSE=0 DEB_PYTHON_INSTALL_LAYOUT=deb_system DEBIAN_FRONTEND=noninteractive VIRTUAL_ENV=/test-env OMPI_ALLOW_RUN_AS_ROOT=1 OMPI_ALLOW_RUN_AS_ROOT_CONFIRM=1 HOME=/root Hydra internal environment: --------------------------- GFORTRAN_UNBUFFERED_PRECONNECTED=y Proxy information: ********************* [1] proxy: 6a2e05040a65 (1 cores) Exec list: python3 (2 processes); ================================================================================================== Proxy launch args: /usr/bin/hydra_pmi_proxy --control-port 6a2e05040a65:36819 --debug --rmk user --launcher ssh --demux poll --pgid 0 --retries 10 --usize -2 --pmi-port 0 --gpus-per-proc -2 --gpu-subdevs-per-proc -2 --proxy-id Arguments being passed to proxy 0: --version 4.2.0 --iface-ip-env-name MPIR_CVAR_CH3_INTERFACE_HOSTNAME --hostname 6a2e05040a65 --global-core-map 0,1,1 --pmi-id-map 0,0 --global-process-count 2 --auto-cleanup 1 --pmi-kvsname kvs_1_0_1589598326_6a2e05040a65 --pmi-process-mapping (vector,(0,1,2)) --global-inherited-env 11 'PATH=//test-env/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin' 'HOSTNAME=6a2e05040a65' 'TERM=xterm' 'OPENBLAS_NUM_THREADS=1' 'OPENBLAS_VERBOSE=0' 'DEB_PYTHON_INSTALL_LAYOUT=deb_system' 'DEBIAN_FRONTEND=noninteractive' 'VIRTUAL_ENV=/test-env' 'OMPI_ALLOW_RUN_AS_ROOT=1' 'OMPI_ALLOW_RUN_AS_ROOT_CONFIRM=1' 'HOME=/root' --global-user-env 0 --global-system-env 1 'GFORTRAN_UNBUFFERED_PRECONNECTED=y' --proxy-core-count 1 --exec --exec-appnum 0 --exec-proc-count 2 --exec-local-env 0 --exec-wdir /tmp --exec-args 3 python3 -c from mpi4py import MPI; print(f'{MPI.COMM_WORLD.rank}/{MPI.COMM_WORLD.size}'); [mpiexec@6a2e05040a65] Launch arguments: /usr/bin/hydra_pmi_proxy --control-port 6a2e05040a65:36819 --debug --rmk user --launcher ssh --demux poll --pgid 0 --retries 10 --usize -2 --pmi-port 0 --gpus-per-proc -2 --gpu-subdevs-per-proc -2 --proxy-id 0 [proxy:0@6a2e05040a65] Sending upstream hdr.cmd = CMD_PID_LIST [proxy:0@6a2e05040a65] Sending upstream hdr.cmd = CMD_STDOUT [proxy:0@6a2e05040a65] Sending upstream hdr.cmd = CMD_STDOUT 0/1 0/1 [proxy:0@6a2e05040a65] Sending upstream hdr.cmd = CMD_EXIT_STATUS ``` Best, Jørgen -- *Jørgen S. Dokken, *PhD Senior Research Engineer Simula Research Laboratory +47 45286467