Hi Simon, I think you might actually need CFLAGS=’-std=gnu99’
Randy M. > On Aug 4, 2022, at 1:51 PM, Satish Balay via petsc-users > <petsc-users@mcs.anl.gov> wrote: > >> Configure Options: --configModules=PETSc.Configure >> --optionsModule=config.compilerOptions CFLAGS=-std=c99 --with-cc=mpicc >> --with-cxx=g++ --download-fblaslapack=yes --download-hypre=yes -with-x=0 >> --with-c++support=yes --with-mpi=yes --with-hypre=yes --prefix=/petsc >> --with-c2html=0 --with-ssl=0 > > Try: > > ./configure CFLAGS=-std=c99 --with-cc=mpicc --with-cxx=mpicxx > --with-fc=mpif90 --download-fblaslapack=yes --download-hypre=yes -with-x=0 > --with-c2html=0 --with-ssl=0 > > Satish > > On Thu, 4 Aug 2022, Simon Zhang wrote: > >> I do have mpicc installed and have CFLAGS=-std=c99 but I'm still unable to >> configure. >> >> On Thu, Aug 4, 2022 at 12:21 PM Satish Balay <ba...@mcs.anl.gov> wrote: >> >>>> gcc (Ubuntu 4.8.4-2ubuntu1~14.04.4) 4.8.4 >>> >>> Do you have a newer gcc version available for use on this machine? >>> >>>>>>>>> >>> /tmp/petsc-7thm2vwz/config.setCompilers/conftest.c: At top level: >>> cc1: warning: unrecognized command line option "-Wno-lto-type-mismatch" >>> [enabled by default] >>> >>> Rejecting compiler flag -std=c99 due to >>> <<<<<< >>> >>> Hm - looks configure logic here is failing. >>> >>> -Wno-lto-type-mismatch checked went through earlier [so this flag was >>> accepted] - but then when a test is retried with "-Wno-lto-type-mismatch >>> -std=c99" its failing >>> >>> Perhaps one way to work around is to use configure option: CFLAGS=-std=c99 >>> >>> But its better to use a more recent gcc than 4.8.4 >>> >>> Satish >>> >>> On Thu, 4 Aug 2022, Simon Zhang wrote: >>> >>>> On Thu, Aug 4, 2022 at 10:05 AM Satish Balay <ba...@mcs.anl.gov> wrote: >>>> >>>>> please send the corresponding configure.log >>>>> >>>>> Satish >>>>> >>>>> On Thu, 4 Aug 2022, Simon Zhang wrote: >>>>> >>>>>> To whom it may concern, >>>>>> >>>>>> I'm trying to install PETSc on my computer and PETSc is compliant >>> with >>>>> GCC >>>>>> but something keeps going wrong at the compilation step. It's >>> returning >>>>> the >>>>>> following message. >>>>>> >>>>>> PETSc requires c99 compiler! Configure could not determine compatible >>>>>> compiler flag. >>>>>> >>>>>> How can I fix this problem? >>>>>> >>>>>> Thank you, >>>>>> Simon Zhang >>>>>> >>>>> >>>>> >>>> >>> >>> >> >