I am trying to port MPICH to CHERI ( https://www.cl.cam.ac.uk/research/security/ctsrd/cheri/cheri-morello.html). I have forgotten some of the tricks of porting to weird stuff that I used to know when I was working on Blue Gene. Can someone help me figure out how to configure for an unknown tuple? I am failing to find the answer myself. Thanks, Jeff jhammond@cfarm240:~/mpich/build$ ../configure CC=clang --disable-fortran --disable-long-double --enable-g=all Configuring MPICH version 4.2a1 with 'CC=clang' '--disable-fortran' '--disable-long-double' '--enable-g=all' Running on system: FreeBSD cfarm240.cfarm.net 14.0-CURRENT FreeBSD 14.0-CURRENT #0 772f8fd8123: Mon Aug 7 19:39:52 UTC 2023 jenkins@ctsrd-build-linux-j1 :/local/scratch/jenkins/workspace/CheriBSD-pipeline_releng_22.12@2 /cheribsd-morello-purecap-build/local/scratch/jenkins/workspace/CheriBSD-pipeline_releng_22.12@2/cheribsd/arm64.aarch64c/sys/GENERIC-MORELLO arm64 checking build system type... Invalid configuration `aarch64c-unknown-freebsd14.0': machine `aarch64c-unknown' not recognized configure: error: /bin/sh ../confdb/config.sub aarch64c-unknown-freebsd14.0 failed jhammond@cfarm240:~/mpich/build$ clang --version clang version 13.0.0 Target: aarch64-unknown-freebsd14.0 Thread model: posix InstalledDir: /usr/local64/llvm-morello/bin -- Jeff Hammond [email protected] http://jeffhammond.github.io/