On Sat, Nov 15, 2025 at 01:27:24AM +0100, José Luis García Pallero wrote: > The definition of > > export OMPI_MCA_btl_tcp_if_include=lo > > makes dissapear the warning. What does it mean?
It tells OpenMPI to only use the loopback interface (lo) for TCP communication. In this way, MPI processes can only communicate with each other on the same machine, not across a network. I assume you have a single machine here, so the above variable will still allow you to use OpenMPI normally. [ Can we close this bug? The message you see is just a warning, it does not affect normal operation ] Thanks.
