Re: [igraph] Igraph python install problem

[Tamas Nepusz]

Hi,

> It seemed to install OK, but when I try and import igraph or run the  
> test.py script I get:
>
> Traceback (most recent call last):
>   File "..../python/python-igraph-0.5.1/test.py", line 11, in <module>
>     import igraph.test
>   File "build/lib.linux-x86_64-2.5/igraph/__init__.py", line 30, in  
> <module>
> ImportError: /bmm/home/dc101/python/lib/python2.5/site-packages/ 
> igraph/core.so: undefined symbol: igraph_vector_destroy
This is because although gcc was able to find the igraph library  
during the linking phase (when it created the actual .so files for the  
Python extension), it is not able to find that anymore when you try to  
import it. The reason is that you installed the igraph library  
(libigraph.so.*) in your home directory somewhere and not in one of  
the default system library paths (/lib, /usr/lib, /usr/local/lib). The  
solution is to explicitly extend the library path to include the  
directory where you put igraph. E.g., if you put it in /home/dan/my- 
stuff/lib, then you should do the following:

export LD_LIBRARY_PATH=/home/dan/my-stuff/lib
python
>>> import igraph

I think the system's library path can also be extended permanently by  
adjusting something in one of the config files in /etc and then  
calling ldconfig to reload the library caches, but I'm not sure.

Anyway, if you have a Debian system, you might find it easier to  
install igraph from our package repository (see the Download page on  
the homepage for instructions). Fedora packages are also available.

--
T.