> 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 > > > > > > > >