When I run my GWT 2.6 + GXT 3.1.1 project in "Super Dev Mode", compilation with the code server ignores bindings of user.agent (such as user.agent=safari). As a result, it builds more permutations than necessary and it can't load the source map ("java.lang.RuntimeException: Multiple fragment 0 sourcemaps found. Too many permutations."). If instead you specify a value for gxt.user.agent, it compiles only one permutation, as desired.

Why is this? What can I do about it?