Dear Developers, I am Songchen Tan at UC Berkeley, recently I am trying to use MPICH on macOS 10.15. Though binaries via homebrew is available, I would like to build from source in order to configure it with Intel compilers (icc, icpc and ifort). To reproduce the problem: 1. Download the source in ~/Applications/; 2. Unzip with `tar -xvzf mpich-3.3.2.tar.gz`, then `cd mpich-3.3.2`; 3. Run `./configure --prefix=/usr/local/Cellar/mpich/3.3.2 CC=icc CXX=icpc F77=ifort FC=ifort 2>&1 | tee c.txt`; 4. Build with `make VERBOSE=1 2>&1 | tee m.txt`. 5. Then I am noticed: `Undefined symbols for architecture x86_64: “__ZTHMPIR_Per_thread”`. The generated `c.txt` and `m.txt` is attached. Thank you so much for your help. Sincerely yours, Songchen Songchen Tan 10292504 College of Chemistry, University of California, Berkeley 97420, U. S. A. Email: [email protected] Cell: (+86)13501382788