If the CDI backend fails when getting the value for a variable put the error message in place of the value string so the user will have some idea what happened.

debug/org.eclipse.cdt.debug.core/src/org/eclipse/cdt/debug/internal/core/model/CValue.java

@@ -98,6 +98,7 @@ public class CValue extends AbstractCValue {
 				}
 				catch( CDIException e ) {
 					setStatus( ICDebugElementStatus.ERROR, e.getMessage() );
+					fValueString = e.getLocalizedMessage();
 				}
 			}
 		}