[petsc-dev] [petsc-maint #68731] Installation problem with petsc4py

[Barry Smith]

On Mar 30, 2011, at 2:49 PM, David Maxwell wrote:

> Barry, Andy:
> 
> I suppose you can avoid both these gotchas by involving the end user in the choice rather than making it arbitrarily.  For example, in reconfigure:
> 
> * Don't hardwire the python executable, but
> 
> * Check that the python executable running the script is the original one (compare sys.executable with a stored value).
> 
> If there is a mismatch, print a meaningful error message telling the user to either run the script explicitly with the original python, or to set a command line flag indicating the current python is to be used (and is then a part of the reconfiguration).

   Good idea. Satish, unless you can find a problem with this suggestion could you please make this change.

> 
> Speaking of meaningful error messages, the message from petsc4py.Configure.configureLibrary:
> 
> realpath of /usr/lib/libpython.dylib (/System/Library/Frameworks/Python.framework/Versions/2.6/Python) does not point to Python library path (/Library/Frameworks/Python.framework/Versions/6.1/Python) for current Python;
> Are you not using the Apple python?

   Fixed.

   Barry


> 
> is misleading since the current python library path is not obliged to be /usr/lib/libpython's realpath, but can also be one of a handful of hardcoded macports pythons as well.
> 
> -David
> 
> 
>> 
>>  We've had endless discussions about this. If we don't hardwire it and someone runs the reconfigure... after a path change then they get something different and get very confused. If we do hardware it then it cannot easily use a different python the way a user might think it would. We've had people screwed on both sides of this (we didn't used to hardware it).
>> 
>>  If you have a solution distinct from those two flawed schemes we'd love to try it.
>> 
>>  Barry
>> 
>>> 
>>> Cheers,
>>> 
>>> Andy
>>> 
>>> 
>>> On Mar 29, 2011, at 11:09 PM, Matthew Knepley wrote:
>>> 
>>>> On Tue, Mar 29, 2011 at 9:18 PM, Andy Aschwanden <andy.aschwanden at arsc.edu> wrote:
>>>> Dear PETSc developers
>>>> 
>>>> I'm trying to install petsc-3.1-p4 with --download-petsc4py on my OSX 10.6, and get the following error:
>>>> 
>>>>     TESTING: configureLibrary from PETSc.packages.petsc4py(config/PETSc/packages/petsc4py.py:43)                             *******************************************************************************
>>>>      UNABLE to CONFIGURE with GIVEN OPTIONS    (see configure.log for details):
>>>> -------------------------------------------------------------------------------
>>>> realpath of /usr/lib/libpython.dylib (/System/Library/Frameworks/Python.framework/Versions/2.6/Python) does not point to Python library path (/Library/Frameworks/Python.framework/Versions/6.1/Python) for current Python;
>>>> Are you not using the Apple python?
>>>> 
>>>> Detailed configure.log is attached.
>>>> 
>>>> The answer to the above question is: I'm *NOT* using the Apple python, instead I have python26 installed via MacPorts. There are, however, various python installations on my system, including an EPD 6.1 in /Library/Frameworks/Python.framework/Versions/6.1/Python.
>>>> 
>>>> I will look at the log, but this install is no longer the easiest one. If you just install
>>>> PETSc, and then use
>>>> 
>>>> pip install petsc4py
>>>> 
>>>> when you have PETSC_DIR and PETSC_ARCH defined, it should work.
>>>> 
>>>> Thanks,
>>>> 
>>>>  Matt
>>>> 
>>>> I did
>>>> $ python_select python26
>>>> to select the MacPorts python distribution I want to use with petsc4py, and indeed
>>>> 
>>>> $ which python
>>>> /opt/local/bin/python
>>>> 
>>>> points to the right place. I don't know why petsc picks up the wrong python. Is there a way to tell petsc which python version it should use for petsc4py.
>>>> 
>>>> 
>>>> Thanks,
>>>> 
>>>> Andy
>>>> 
>>>> CC: David Maxwell
>>>> 
>>>> 
>>>> Dr. Andy Aschwanden
>>>> ARSC Postdoctoral Fellow
>>>> Geophysical Institute
>>>> 903 Koyukuk Drive
>>>> Fairbanks AK 99775
>>>> USA
>>>> 
>>>> email   andy.aschwanden at arsc.edu
>>>> phone +1 (907) 474-7199
>>>> fax      +1 (907) 474-7290
>>>> 
>>>> 
>>>> 
>>>> 
>>>> 
>>>> 
>>>> -- 
>>>> What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead.
>>>> -- Norbert Wiener
>>> 
>>> Dr. Andy Aschwanden
>>> ARSC Postdoctoral Fellow
>>> Geophysical Institute
>>> 903 Koyukuk Drive
>>> Fairbanks AK 99775
>>> USA
>>> 
>>> email   andy.aschwanden at arsc.edu
>>> phone +1 (907) 474-7199
>>> fax      +1 (907) 474-7290
>>> 
>>> 
>>> 
>>> 
>> 
> 
>