No subject

   ./configure --with-cc=gcc --with-fc=gfortran --download-f-blas-lapack
   --download-mpich --without-x

It looks like you have mpi installed on your machine, and it is
conflicting with the one you downloaded for Petsc.  So you should just
use the mpi on your machine.  In particular, try configuring Petsc with something like

   ./configure --download-f-blas-lapack --without-x

Make sure that you have libopenmpi-dev or openmpi-dev installed.

In fact, since you are on Ubuntu, you can also get rid of the
"--download-f-blas-lapack" option by installing liblapack-dev and
libblas-dev.

Cheers,
Walter Landry