Unable to build prerequisite module: Math-SymbolicX-NoSimplification (0) Unable to build prerequisite module: Number-WithError (0.03) Unable to build prerequisite module: Math-SymbolicX-Error (0) Unable to build prerequisite module: Math-Symbolic (0) Unable to build prerequisite module: Gtk2-Ex-Dialogs (0) Unable to build prerequisite module: Gtk2 (0) App-ErrorCalculator could not be built due to the above failed prerequisites.