Hi, I have an issue with mpich. I have been using mpich with no problem so far, installed as standard package in debian 11 on my 12-core PC. I found mpich superior to intel mpi. After I have recently upgraded to debian 12 (bookworm), trying to call mpich with the script mpif90, I get a long series of errors (both with gfortran and ifort - in the latter case with FC="ifort"), basically a multiplication of the following sequence: ------ /usr/bin/ld: /usr/lib/x86_64-linux-gnu/libmpich.a(lib_libmpich_la-pready.o): in function `PMPI_Pready': (.text+0x7b3): undefined reference to `ucp_am_send_nb' /usr/bin/ld: (.text+0x7e7): undefined reference to `ucp_request_release' /usr/bin/ld: (.text+0xb68): undefined reference to `ucs_status_string' ------- I assume some library or dependency is missing, or maybe the new debian package is broken. I am asking your support since I could not find help online. Best regards Andrea Buzzi Associate senior scientist Istituto di Scienze dell'Atmosfera e del Clima - CNR-ISAC Institute of Atmospheric Sciences and Climate - CNR-ISAC Via Gobetti 101, I-40129 Bologna email: [email protected] -- Andrea Buzzi Associate senior scientist Istituto di Scienze dell'Atmosfera e del Clima - CNR-ISAC Institute of Atmospheric Sciences and Climate - CNR-ISAC Via Gobetti 101, I-40129 Bologna email: [email protected]