compiled on RPI4B-4G with 5.10.77-piCore-v8 Compile Flags: CFLAGS='-march=armv8-a+crc -mtune=cortex-a72 -Os -pipe -flto -fuse-linker-plugin' CXXFLAGS='-march=armv8-a+crc -mtune=cortex-a72 -Os -pipe -flto -fuse-linker-plugin -fno-rtti' LDFLAGS='-Wl,-O1' Can not use -fexceptions flag: src/binding/cxx/initcxx.cxx: In member function ‘virtual void MPI::Comm::Call_errhandler(int) cons: src/binding/cxx/initcxx.cxx:735:34: error: exception handling disabled, use ‘-fexceptions’ to enable 735 | throw Exception(errorcode); // throw by value, catch by reference | Dependencies: compiletc libfabric-dev perl5 Commands: tar xf cd mpich-3.4.3 time ./configure --prefix=/usr/local --with-gnu-ld --disable-fortran --with-device=ch4:ofi *** *** device: ch4 *** netmods: ofi *** shm: auto *** Configuration completed. real 5m 27.71s user 4m 0.87s sys 2m 22.39s find -name Makefile -exec sed -i 's/-O2//g' {} + time make -j4 real 36m 51.58s user 1h 17m 09s sys 11m 28.56s