The following error occurs when triggering content assist on a JPA annotation attribute of any Entity in the project (after following instructions on http://www.jboss.org/ticket-monster/datapersistence/)
Java Model Exception: Java Model Status [/Users/xcoulon/.m2/repository/org/hibernate/javax/persistence/hibernate-jpa-2.0-api/1.0.1.Final/hibernate-jpa-2.0-api-1.0.1.Final.jar is not on its project's build path] at org.eclipse.jdt.internal.core.PackageFragmentRoot.getRawClasspathEntry(PackageFragmentRoot.java:562) at org.eclipse.jdt.internal.core.JavaElement.getJavadocBaseLocation(JavaElement.java:714) at org.eclipse.jdt.internal.core.BinaryType.getJavadocContents(BinaryType.java:1011) at org.eclipse.jdt.internal.core.BinaryField.getAttachedJavadoc(BinaryField.java:121) at org.eclipse.jdt.internal.core.ResolvedBinaryField.getAttachedJavadoc(ResolvedBinaryField.java:1) at org.eclipse.jdt.internal.ui.text.javadoc.JavadocContentAccess2.getHTMLContent(JavadocContentAccess2.java:500) at org.eclipse.jdt.internal.ui.text.java.hover.JavadocHover.getHoverInfo(JavadocHover.java:689) at org.eclipse.jdt.internal.ui.text.java.hover.JavadocHover.internalGetHoverInfo(JavadocHover.java:607) at org.eclipse.jdt.internal.ui.text.java.hover.JavadocHover.getHoverInfo2(JavadocHover.java:599) at org.eclipse.jdt.internal.ui.text.java.hover.BestMatchHover.getHoverInfo2(BestMatchHover.java:163) at org.eclipse.jdt.internal.ui.text.java.hover.BestMatchHover.getHoverInfo2(BestMatchHover.java:129) at org.eclipse.jdt.internal.ui.text.java.hover.JavaEditorTextHoverProxy.getHoverInfo2(JavaEditorTextHoverProxy.java:85) at org.eclipse.jface.text.TextViewerHoverManager$4.run(TextViewerHoverManager.java:166)