We are happy to announce that we just released MPICH-5.0.0rc1. This is the first release candidate for MPICH-5.0.0. It contains some bug fixes and improvements since MPICH-5.0.0b1. See the list of changes below. The release tarball can be found on our downloads page (https://urldefense.us/v3/__https://www.mpich.org/downloads__;!!G_uCfscf7eWS!... ). Please test. List of changes since v5.0.0b1: yaksa: fix automatic compilation for CUDA 13 ch4: shm: fix data type for recv_bytes in MPIDI_POSIX_mpi_release_gat… abi: fix MPI_Abi_get_fortran_info yaksa: update to sync-up with yaksa repo ch4: use larger initial av_tables size autogen: pre-run libtoolize if necessary ch4/win: refactor win_shm_alloc_impl hydra: do not use -lhydra to link build: miscellaneous configure and build issues Fix data races found by ThreadSanitizer cma: fix CMA detection makefile: fix missing semicolon in `uninstall-local` abi: do not convert builtin handles in _{from,to}int hydra: fix standalone build on MacOS ch4/progress: fine-tune progress throttle init: add commit hash to DEBUG_SUMMARY misc: ci warnings rollup common/genq: fix false sharing and alignment issue in shared pool misc: fine tune default fast copy threshold -- Hui Zhou on behalf of MPICH Team