Comment 2 for bug 168843

A related issue is that the extension doesn't disable itself at launch if numpy is not installed at launch (as other extensions, like the latex formula extension do, if their dependencies are not present). Running the effect gives the error:

Inkscape has received additional data from the script executed. The script did not return an error, but this may indicate the results will not be as expected.
Failed to import the numpy or numpy.linalg modules. These modules are required by this extension. Please install them and try again.