lombok's compile target is 1.6, but, eclipse project was generated as 1.7. This caused a bunch of weirdness because eclipse changes a bunch of warnings and quickfixes based on this (such as complaining about lack of @SafeVarargs, a 1.7-only feature).

build.xml

@@ -256,7 +256,7 @@ the common tasks and can be called on to run the main aspects of all the sub-scr
 	</target>
 	
 	<target name="eclipse" depends="deps, contrib" description="Creates eclipse project files and downloads all dependencies. Open this directory as project in eclipse after running this target.">
-		<ivy:eclipsegen>
+		<ivy:eclipsegen source="1.6">
 			<srcdir dir="src/core" />
 			<srcdir dir="src/utils" />
 			<srcdir dir="src/eclipseAgent" />

src/delombok/lombok/delombok/DelombokApp.java

@@ -84,7 +84,6 @@ public class DelombokApp extends LombokApp {
 			return null;
 		}
 		
-		@SuppressWarnings("resource")
 		final JarFile toolsJarFile = new JarFile(toolsJar);
 		
 		ClassLoader loader = new ClassLoader() {