My job consists mostly of Java programming. Over the past several months, the following things have been happening:

• I have started doing a lot of work with GWT.
• I have become enthusiastic about building a Java library (org.jreact - I've already bought the domain name) which should be helpful with GWT development.
• I have been introduced to Scala, which has made me increasingly aware and sick of Java's shortcomings.
• I have encountered a fledgling project, which aims to adapt the GWT compilation process to Scala code.

So, there are two different paths I want to take to help advance client-side web development.

There's no shortage of Java things to be frustrated about.

public class Fail {

  static interface A { }
  static interface B { }
  static interface C extends A, B {}

  static interface D { A x(); }
  static interface E { B x(); }
  static interface F extends D, E { C x(); }

}

I see no legitimate reason why this should not compile. But javac disagrees:

Fail.java:9: types Fail.E and Fail.D are incompatible; both define x(), but with unrelated return types

IntelliJ IDEA, however, doesn't see a problem with this code. Although I agree with it, I've submitted a bug report.

I don't understand why no one else seems to be complaining about this bug, because lately I can't seem to avoid it.

Perhaps I was too hasty in posting the bug report a few days ago, because I've discovered now that it happens in more cases than I thought. A namespace clash is not even necessary. You can change the package name and get the same error:

/* One.java */
package abc;
import static abc.Two.three;
public class One<A> { }

/* Two.java */
package abc;
public class Two<B> extends One<B> {
    public static Object three;
}

This is absurd.