A developer found pants 'FAILURE: deduced and actual class name mismatch' misleading

[ericzundel]

jmake: Could not find class file for /Users/cconroy/Development/java/tracon/src/test/java/com/squareup/tracon/protocol/http/match/Foo.java
                         Warning: unable to find .class file corresponding to source /Users/cconroy/Development/java/tracon/src/test/java/com/squareup/tracon/protocol/http/match/Foo.java: expected /Users/cconroy/Development/java/.pants.d/compile/jvm/java/classes/Foo.class

This is a frequently seen error from jmake and can cause some head scratching. There are several different classes of problems that cause this error:

• multiple top level classes in one source file
• package name different from source path
• in this case, the class was commented out.

It might be nice to add some extra logic to jmake to try to guess which problem this is and give better diagnostics.