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Here's a blog post from someone who has worked around this on Windows:
http://www.jacobpennock.com/Blog/?p=568

It appears that the issue is that Unity (and some other text editors) uses ';' as the delimiter between filename and line number.  Sublime uses ':' as the delimiter.

Is there a way to handle this with a Python plugin for sublime, or a way to retrieve the full name of the file being opened (along with the ;[linenum] part)?