Comment 7 for bug 902843

> Do you know the parameters Inkscape uses to call scour?

Did you use the default options? Those are defined in
'/Applications/Inkscape.app/Contents/Resources/extensions/scour-inkscape.py'
(in 'def __init__(self):')

The last used options are saved in the preferences file
'~/.config/inkscape/preferences.xml'
(search for 'org.inkscape.output.scour.')

The settings from 'preferences.xml' override the default values defined in 'scour.inkscape.py'.