With the creation of the NestedSequential representation of the nested sequential task of macrodef, the Location from the original sequential task is lost. Therefore when the MacroDef "fakes" out the new UnknownElement in getNestedTask () it is not possible for this element to have the correct Location as it cannot be passed on from the nestedSequential object. This comes into play for the Eclipse Ant debugger...the sequential task in the debugger stack trace always shows the unknown location. I would request that if possible changes be made to provide the location for the sequential task in this case.