Hi there! To answer my previous question myself: The trouble with dl and the like ceases once one creates a DLFCN.py file via the h2py.py script inside the python 2.7 source distribution. This file must be kept somewhere reachable to python - for example in the graph-tool python directory. Morever, I fixed the problem with the wrong installation paths in the Portfile. As a result I obtained a fully working graph-tool inside macports. Note, that I compile numpy and scipy with the apple gcc which is not the default in Macports. When loading graph-tool, I get though this error: Traceback (most recent call last): File "../../python/grid2gml.py", line 3, in <module> from graph_tool.all import * File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/graph_tool/all.py", line 31, in <module> from graph_tool.draw import * File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/graph_tool/draw/__init__.py", line 69, in <module> libc.open_memstream.restype = ctypes.POINTER(ctypes.c_char) File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/ctypes/__init__.py", line 366, in __getattr__ func = self.__getitem__(name) File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/ctypes/__init__.py", line 371, in __getitem__ func = self._FuncPtr((name_or_ordinal, self)) AttributeError: dlsym(RTLD_DEFAULT, open_memstream): symbol not found This seems to relate to new changes in git. Included is the Portfile I used which now has openmp disabled by default, since this will crash the apple gcc anyway... Cheers, -- Sebastian Weber Group of Cell Communication and Control Freiburg Institute for Advanced Studies - FRIAS School of Life Sciences - LIFENET Albert-Ludwigs-Universität Freiburg Albertstr. 19 79104 Freiburg T.: +49-761-203-97237 Fax:+49-761-203-97334