Eclipse has a more nitpicky compiler than the standard javac, and jenkins and other tools can collect these warnings.
Buildr helpfully, has a way of installing and running the compiler, here is an example:
{{
load 'buildfile.dependencies'
require 'buildr/java/ecj'
include Buildr::Compiler
define "project-ecj" do
options.test = "no"
compile.with(DEPENDENCIES)
compile.using(
:warnings=>true,
:debug=>true,
:deprecation=>true,
:target=>'1.6',
:source=>'1.6',
:lint=>true,
The ecj.rb file is hardcoded to version 3.5.1, which is pretty old. You can update to 4.2.2 (or later) by using the build.yaml , or setting the version number in the extension directly (not recommended).