fix #986: add @Target and @Retention to @Builder.ObtainVia

doc/changelog.markdown

@@ -18,6 +18,7 @@ Lombok Changelog
 * BUGFIX: When using delombok, a source file with only `@NonNull` annotations on parameters as lombok feature would not get properly delomboked.  [Issue #950](https://github.com/rzwitserloot/lombok/issues/950).
 * BUGFIX: `@Delegate` in javac would generate arrays instead of varargs parameters. [Issue #932](https://github.com/rzwitserloot/lombok/issues/932).
 * BUGFIX: `@Value` and `@FieldDefaults` no longer make uninitialized static fields final. [Issue #928](https://github.com/rzwitserloot/lombok/issues/928).
+* ENHANCEMENT: `@Builder.ObtainVia` now has `@Retention(SOURCE)` [Issue #986](https://github.com/rzwitserloot/lombok/issues/986).
 * ENHANCEMENT: Putting `@NonNull` on a parameter of an abstract method no longer generates a warning, to allow you to use this annotation to document intended behaviour [Issue #807](https://github.com/rzwitserloot/lombok/issues/807).
 
 ### v1.16.6 (August 18th, 2015)

src/core/lombok/Builder.java

@@ -139,6 +139,8 @@ public @interface Builder {
 	 * <p>
 	 * The default behaviour is to obtain a value by referencing the name of the parameter as a field on 'this'.
 	 */
+	@Target({FIELD, PARAMETER})
+	@Retention(SOURCE)
 	public @interface ObtainVia {
 		/** Tells lombok to obtain a value with the expression {@code this.value}. */
 		String field() default "";