[petsc-dev] PETSc-3.4 PR open at https://github.com/Homebrew/homebrew-science/pull/343

[Dominique Orban]

On 2013-10-12, at 11:38 AM, Aron Ahmadia <aron at ahmadia.net> wrote:

>> I think we decided that with prefix installs, people use a different
>> prefix to distinguish different PETSC_ARCH.  Do you want to revisit that
>> choice?
> 
> I'm okay with using a different prefix to determine a different
> PETSC_ARCH.  This is one of the core ideas facilitated by HashDist.  I
> just wanted to raise it up as another option.

So this is perhaps something I'm misunderstanding from the PETSc install instructions. If I set the prefix to, say, /usr/local/petsc, everything will be installed under /usr/local/petsc, not under /usr/local/petsc/$PETSC_ARCH.

TAO, which builds upon PETSc, installs in $TAO_DIR/$PETSC_ARCH by default. But it looks for PETSc stuff under $PETSC_DIR/$PETSC_ARCH. So when I install TAO, I have to trick it by temporarily unsetting PETSC_ARCH.

SLEPc doesn't go look for stuff in $PETSC_DIR/$PETSC_ARCH.

Unless I'm missing something, I think there's room for some standardization here. I could just set the PETSc prefix to /usr/local/petsc/$PETSC_ARCH but technically, PETSC_ARCH isn't known at configure time. It would make sense to me if PETSc installed everything that's machine-dependent under $PETSC_DIR/$PETSC_ARCH and everything that's common to all architectures (the .h files perhaps?) under $PETSC_DIR. But this needs to be synchronized with other major projects that use PETSc.

Dominique