[SciPy-User] undefined symbol: clange_

[Nathaniel Smith]

On Sat, Jul 5, 2014 at 3:39 PM, Ralf Gommers <ralf.gommers at gmail.com> wrote:
>
> On Sat, Jul 5, 2014 at 4:27 PM, Nathaniel Smith <njs at pobox.com> wrote:
>>
>> On Debian testing, py27, x86-64:
>>
>> sudo apt-get build-dep python-scipy
>> . myvenv/bin/activate
>> pip uninstall scipy
>> pip install scipy==0.14.0
>> python -c 'import scipy.linalg'
>>
>> gives me:
>>
>> ImportError:
>> /home/njs/.user-python2.7-64bit-3/local/lib/python2.7/site-packages/scipy/linalg/_fblas.so:
>> undefined symbol: clange_
>>
>> Any ideas how to build a non-broken scipy here? Rebuilding this
>> virtualenv from scratch would be tiresome...
>
> Never seen this one before. Does pip leave something behind after uninstall?
> Any idea if it's specific to this version of Debian or your set of
> compilers?

After a lucky guess, I've determined that the problem had something to
do with the BLAS installation -- I had both openblas and atlas
installed, with Debian's "alternatives" set to default to openblas. I
uninstalled openblas (apt-get remove libopenblas-base) and rebuilt,
and now everything works. So I don't know exactly what the problem
was, but it looks like some sort of nasty interaction between which
library was being built against versus what library was being used at
runtime, or something along those lines.

-n

-- 
Nathaniel J. Smith
Postdoctoral researcher - Informatics - University of Edinburgh
http://vorpus.org