Unfortunately there is no option to disable real128 or complex128 at the moment. You can remove them by editing src/binding/fortran/use_mpi_f08/mpi_f08_types.f90, search for “real128” and “complex128”, remove the lines declaring them as well as the two subroutines below.

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Hui Zhou

From: Blaise A Bourdin via discuss <discuss@mpich.org>
Date: Sunday, March 7, 2021 at 7:15 AM
To: discuss@mpich.org <discuss@mpich.org>
Cc: Blaise A Bourdin <bourdin@lsu.edu>
Subject: [mpich-discuss] Build failure on macOS Big Sur arm64

So it looks like in this case, the f08 bindings for real128 and complex128 are created even though they shouldn’t. I was not able to figure out how to disable their creation during the configure stage. Can somebody help? My config.log is attached.