Xcode error: "The argument is invalid"

If you get this error while publishing from Xcode, you may have a rogue symlink in your project. As of Xcode 4.1, symlinks will give you the awesome, helpful error: "The argument is invalid"

Check your project for symlinks, and remove them. If you're symlinking another directory into your project, this would work in the iOS Simulator, but not on a device, so you'd probably want to come up with another strategy for including files from another project. To help with finding symlinks, run the following command from the root of your project directory. It will list any symlinks and their original location.

find ./ -type l -exec ls -l {} \;