After successfully building QGIS 1.8 "Lisboa" on Windows 7 in 32 bit mode by following the instructions mentioned here I am able to start QGIS, however I get the following startup error message:

Couldn't load PyQt4. Python support will be disabled.

Traceback (most recent call last): File "", line 1, in ImportError: DLL load failed: The specified procedure could not be found.

Python version: 2.7.2 (default, Jun 12 2011, 15:08:59) [MSC v.1500 32 bit (Intel)]

QGIS version: 1.8.0-Lisboa 'Lisboa', exported

After this message the Python console and other python related plugins are not loaded.

I have installed the latest PyQt installer of PyQt4.9.5 from riverbanks

My system details

OS: windows 7 64 bit

Build tools:

  1. MS Visual Studio 2010
  2. C-Make 2.8.8
  3. Python2.7
  4. PyQt4.9.5 with SIP
  5. OSGeo4W with GRASS and all dependency libs

further investigation lead me to believe that there might be a mismatch of PyQt 4.9.5 that I installed and the one downloaded by OSGeo4W (PyQt4.8). However, I do not know how to make the cmake look for pyQt4.9.5 instead of PyQt4.8

I would highly appreciate any pointers and detailed help in solving this issue.

With regards


  • Perhaps the installer would give you success? hub.qgis.org/projects/quantum-gis/wiki/… What is your use case? – Willy Nov 25 '12 at 10:46
  • Thank you for your response Willy. My use case is as following: – Sukesh Nov 27 '12 at 7:08
  • I need to customize QGIS, hence need to build it from sources and add few customized algorithms to it. I have been able to build QGIS successfully except for the python part. I would appreciate if you could point out how I can resolve PyQt mismatch. Will OSGeo4W libs be updated with PyQt4.9.5 in near future? if not where can I get PyQt4.8 version. Thanks in advance for any help – Sukesh Nov 27 '12 at 7:16
  • Did you try the dev mailing list? lists.osgeo.org/mailman/listinfo/qgis-developer – Willy Nov 27 '12 at 11:09

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