Hi Junchao, Not sure what happened. Do you have the output log for configure and make? Hui ________________________________ From: Junchao Zhang via discuss <[email protected]> Sent: Monday, July 19, 2021 2:59 PM To: [email protected] <[email protected]> Cc: Junchao Zhang <[email protected]> Subject: [mpich-discuss] Build failed with Undefined symbols Hello, I configured mpich/main (or 4.0a2) with ./configure CC=gcc CXX=g++ --enable-fortran=no on Mac with Apple clang version 12.0.5 (clang-1205.0.22.11). The build failed with ... CCLD hydra_pmi_proxy Undefined symbols for architecture x86_64: "_hwloc_topology_set_io_types_filter", referenced from: _HYDT_topo_hwloc_init in libhydra.a(topo_hwloc.o) --Junchao Zhang