[realSlavojTrump]

This is most certainly an area that needs improvement.

You can get around some of the pain of haning error types in catch statements if you are comfortable paying the price for a locally defined function:

result = try Something() catch err h!(e)=throw(e) h!(e::MethodError) = SomethingElse() h!(err) end

This pattern works well if an error case should return a default value and all others should throw.