[petsc-users] configure error with fftw and without mpi

[Fabio Rossi]

Thank you Barry!

Backported the patch to 3.16.0 and tested! I'll try to integrate downstream in Gentoo (https://bugs.gentoo.org/827185).

Fabio

> Il 26/11/2021 05:15 Barry Smith <bsmith at petsc.dev> ha scritto:
> 
> 
> 
> I have made a branch barry/2021-11-25/feature-fftw-seq https://gitlab.com/petsc/petsc/-/merge_requests/4604 that provides support for using FFTW without MPI, please let us know if you have difficulties with it.
> 
> 
> Barry
> 
> 
> 
> 
> > On Nov 25, 2021, at 5:15 AM, Fabio Rossi via petsc-users <petsc-users at mcs.anl.gov> wrote:
> > 
> > 
> > I am trying to compile petsc with the following options (Gentoo build system):
> > 
> > ./configure --prefix=/usr --build=x86_64-pc-linux-gnu --host=x86_64-pc-linux-gnu --mandir=/usr/share/man --infodir=/usr/share/info --datadir=/usr/share --sysconfdir=/etc --localstatedir=/var/lib --libdir=/usr/lib64/petsc/lib64 scrollOutput=1 FFLAGS=-O2 -pipe -fPIC CFLAGS=-march=core2 -O2 -pipe -fPIC CXXFLAGS=-march=core2 -O2 -pipe -fPIC LDFLAGS=-Wl,-O1 -Wl,--as-needed --prefix=/usr/lib64/petsc --with-shared-libraries --with-single-library --with-clanguage=c --with-petsc-arch=linux-gnu-c-opt --with-precision=double --with-gnu-compilers --with-blas-lapack-lib=-lblas -llapack --with-debugging=0 --with-mpi=0 --with-cc=x86_64-pc-linux-gnu-gcc --with-cxx=x86_64-pc-linux-gnu-g++ --with-fortran=1 --with-fc=x86_64-pc-linux-gnu-gfortran --with-mpi-compilers=0 --with-scalar-type=real --with-windows-graphics=0 --with-matlab=0 --with-cmake:BOOL=1 --with-pthread=1 --with-afterimage=0 --without-hdf5 --with-hypre=0 --without-suitesparse --with-superlu=0 --with-x --with-x11 --with-ptscotch=0
> >  --with-
> >  scalapack=0 --without-mumps --with-imagemagick=0 --with-python=0 --with-boost --with-fftw
> > 
> > so MPI support is disabled, and I get the following configure error:
> > 
> > TESTING: consistencyChecks from config.packages.fftw(/var/tmp/portage/sci-mathematics/petsc-3.15.0/work/petsc-3.15.0/config/BuildSystem/config/package.py:963)
> > TESTING: checkDependencies from config.packages.fftw(/var/tmp/portage/sci-mathematics/petsc-3.15.0/work/petsc-3.15.0/config/BuildSystem/config/package.py:872)
> > *******************************************************************************
> >  UNABLE to CONFIGURE with GIVEN OPTIONS (see configure.log for details):
> > -------------------------------------------------------------------------------
> > Did not find package MPI needed by fftw.
> > Enable the package using --with-mpi
> > 
> > Isn't MPI optional? Where is the error coming from?
> > 
> > If I disable fftw then it compiles successfully.
> > 
> > Fabio
>