Hi all, I run into an error which occurs when I submit a yt script to run on cluster nodes. The script runs successfully from the command line though, and I am NOT running MPI here. The error is as follows: /Traceback (most recent call last): File "MergerTree.py", line 1, in <module> from yt.mods import * File "/turing/home/tszkali2/yt-ppc64/src/yt-hg/yt/mods.py", line 92, in <module> from yt.visualization.api import \ File "/turing/home/tszkali2/yt-ppc64/src/yt-hg/yt/visualization/api.py", line 34, in <module> from plot_collection import \ File "/turing/home/tszkali2/yt-ppc64/src/yt-hg/yt/visualization/plot_collection.py", line 26, in <module> from matplotlib import figure File "/turing/home/tszkali2/yt-ppc64/lib/python2.6/site-packages/matplotlib/figure.py", line 16, in <module> import artist File "/turing/home/tszkali2/yt-ppc64/lib/python2.6/site-packages/matplotlib/artist.py", line 6, in <module> from transforms import Bbox, IdentityTransform, TransformedBbox, TransformedPath File "/turing/home/tszkali2/yt-ppc64/lib/python2.6/site-packages/matplotlib/transforms.py", line 34, in <module> from matplotlib._path import affine_transform ImportError: /turing/home/tszkali2/yt-ppc64/lib/python2.6/site-packages/matplotlib/_path.so: undefined symbol: _ZZN2Py15PythonExtensionINS_22ExtensionModuleBasePtrEE9behaviorsEvE1p/ Apparently it is related to matplotlib. I tried to do something similar to the instructions on the wiki for CrayXT5 Installation (http://yt.enzotools.org/wiki/CrayXT5Installation) in the section 'Running on a compute node', but I still got the same error. Does anyone have ideas on what this means? I appreciate any help from you. Thanks, Tsz Ka