Re: import error undefined symbol: PyUnicodeUCS2_Decode

On Mon, Jan 16, 2012 at 4:39 PM, Jason Horning
<jason(dot)horning(at)bullberrysystems(dot)com> wrote:
> I'm trying to port a Python app from Ubuntu to CentOS 5.5.  When I try to
> import psycopg2, I get this:
>
> ImportError: /usr/lib/python2.6/site-packages/psycopg2/_psycopg.so:
> undefined symbol: PyUnicodeUCS2_Decode
>
> My code is built against python 2.6 and python 2.6 is installed on the
> CentOS machine, but it's not the default Python.  (CentOS becomes very
> unhappy if I try to make 2.6 the default.)
>
> I downloaded and extracted psycopg2 version 2.4.4 from
> http://initd.org/psycopg/download/and have performed the following steps:
>
> python26 setup.py build
> python26 setup.py install

Are you sure it is installed where then it gets imported, i.e. in
</usr/lib/python2.6/site-packages/>?

> Hoping to get lucky, I replaced the _psycopg2.so file on the CentOS box with
> the _psycopg2 from my (working) Ubuntu machine.  That just got me another
> error:
>
> ImportError: can't import mx.DateTime module

This error shouldn't be reported since psycopg 2.4.2. You can install
mx.DateTime to see if it solves the problem though.

> Python 2.6 seems to have been compiled with UCS4, and I am building
> psycopg2 against 2.6, but when I do that it still seems to be looking for a
> UCS2 symbol.

I think you are using two different python executables to build
psycopg and to use it.

> Am I missing a step somewhere?

You may try some solution to keep a clean and consistent Python
environment, such as virtualenv. About psycopg, if it is compiled and
used with a consistent python version, it should work fine for both
USC2 and UCS4 builds.

-- Daniele