This is on an OS X.6 box running Python 2.7 and pip 1.0.2 # at command line: pip install -vvv petsc4py # relevant bits: Downloading/unpacking petsc>=3.2,<3.3 (from petsc4py) Getting page http://pypi.python.org/simple/petsc URLs to search for versions for petsc>=3.2,<3.3 (from petsc4py): * http://pypi.python.org/simple/petsc/ Getting page http://www.mcs.anl.gov/petsc/ ... Skipping page http://ftp.mcs.anl.gov/pub/petsc/release-snapshots/petsc-lite-3.2-p6.tar.gz(... http://pypi.python.org/simple/petsc/) because of Content-Type: application/x-gzip ... Found link http://ftp.mcs.anl.gov/pub/petsc/release-snapshots/petsc-lite-3.2-p6.tar.gz(... http://pypi.python.org/simple/petsc/), version: lite-3.2-p6 The "lite-" prefix is being interpreted as part of the version, which pip doesn't quite know what to do with. It would probably just be easiest to host lite versions in a separate directory ../release-snapshots/lite/petsc-3.2-p6.tar.gz that petsc4py/PyPI can point to. Lisandro can also point to the non-lite versions until a solution is implemented. This is going to be an additional problem: ******************************************************************************* UNABLE to CONFIGURE with GIVEN OPTIONS (see configure.log for details): ------------------------------------------------------------------------------- Fortran compiler you provided with --with-fc=/usr/bin/mpif90 does not work ******************************************************************************* Obviously the Mac doesn't come with /usr/bin/mpif90, so a clean system won't have this either... I think you guys know your options for how to fix this, but let me know if you want my 2 cents :) =AA=