Is it a sandbox issue? how to fix it? (I am implementing a plugin of apple mail)

Maybe this tutorial is out of date( it was written in 2009),but I cannot find a better one. While following it step by step, I was stuck at Loading a Plugin section. Apple mail failed to load the plugin.

here is a screenshot of Console's information. enter image description here

Has anybody else tried to follow this tutorial on OS X 10.9 recently?

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It seems "~/Library/Mail/Bundles/MyPlugin.mailbundle/Contents/Frameworks/Python.framework/Versions/2.7/python" needs code signing. enter image description here

Solution

Yes, this is a sandbox problem: Python Mail plug-ins (and I think all plug-ins) cannot read files outside of their container (the Plugin.mailbundle directory).

If you followed the instructions on the tutorial page you mention, you are probably building an alias build of the plug-in (using python setup.py py2app -A), which means that the plug-in will try and access files from the original source location, which is almost always outside of the sandbox (in your case, it's /Users/greedyint/Desktop).

Try running without -A to make a full build.