We've seen issues with Ubuntu built MPI. Can you try --download-mpich and see if that helps?
Also you don't need --with-clanguage=cxx for complex. PETSc can be built with c99 compilex - i.e "--with-clanguage=c --with-scalar-type=complex" should work. Satish On Fri, 12 Aug 2022, David Knezevic via petsc-users wrote: > I get a configure error when building PETSc 3.17.4 on Ubuntu 22.04. The > configure.log is attached. > > This error seems to only occur when we use --with-clanguage=cxx. We need to > use that object when building with complex numbers. > > Guidance on how to resolve this would be most appreciated. > > Thanks, > David >