I'm trying to learn your python workflow library and decided to try convert as a tutorial. However, if I write "conv x" in Alfred, it always goes to the fallback search (Google etc.). If I try to run the python script convert.py in Terminal, I get
python convert.py 200m/s mph
09:41:50 convert.py:100 DEBUG query : 200m/s
09:41:50 background.py:215 DEBUG Calling [u'/usr/bin/python', '/Users/myusername/Library/Application Support/Alfred 2/Alfred.alfredpreferences/workflows/user.workflow.417268A9-C3A4-4777-B247-D481035658FF/workflow/background.pyc', u'update'] ...
RuntimeError: Bad magic number in .pyc file
09:41:50 background.py:218 ERROR Failed to call task in background
09:41:50 convert.py:57 DEBUG quantity : 200.0 tail : m/s
09:41:50 convert.py:135 CRITICAL Invalid query : No destination unit specified
<?xml version="1.0" encoding="utf-8"?>
<items><item valid="no"><title>No destination unit specified</title><subtitle>For example: 2.5cm in | 178lb kg | 200m/s mph</subtitle><icon>/System/Library/CoreServices/CoreTypes.bundle/Contents/Resources/AlertCautionIcon.icns</icon></item></items>09:41:50 convert.py:153 DEBUG finished
So something happens in background.py and then it doesn't parse the second units correctly.
(But I'm actually more interested in understanding why Alfred doesn't tell an error occured but fell back to Google instead, since that happens also when I try to write something using the workflow library myself.)