If you construct a jQuery.Event( src ) using something that has src.type, the 3.0 code will die if there is not an src.target property. jQuery Mobile uses a pattern where they construct an object and then set properties like target afterwards, which was allowed by 1.x/2.x, so we need to fix this as a regression.
jQuery.Event( src )
Event: Allow constructing a jQuery.Event without a target
@dmethvin ah thanks yeah i was having trouble figuring out exactly where this error was coming from