If you try to publish a django project to azure, without having created a virtual env, you'll get a failure from the preview window and another failure if you go ahead with the publish. Unfortunately, the error messages don't help you very much.

From the preview window, the error is:
Target GenerateGlobalPublishSetting Failed

From the output window, the error is:
C:\Program Files (x86)\MSBuild\Microsoft\VisualStudio\v11.0\Python Tools\Microsoft.PythonTools.Django.targets(391,5): Error MSB4023: Cannot evaluate the item metadata "%(Filename)". The item metadata "%(Filename)" cannot be applied to the path "\Users\username\AppData\Local\Microsoft\MSIPC\CLC-{+XmyJjlMMaObhGfvubNM6bcsWqc=}-{{aaa331f3%3bje659%3bj4ea9%3bj876b%3bje8b25c7b4996}}-{{44f39bf4%3bjbfd2%3bj43d9%3bjb1d2%3bjb6fc53752f1c}}-GIC-{PUC41cvFSJBseO6igtIi9VCrfys=}-{+XmyJjlMMaObhGfvubNM6bcsWqc=}-{{aaa331f3%3bje659%3bj4ea9%3bj876b%3bje8b25c7b4996}}-Default.drm". The specified path, file name, or both are too long. The fully qualified file name must be less than 260 characters, and the directory name must be less than 248 characters.