This area displays:
stderr
(standard error port) from projects when they
are executed in the IDE
If there are any compile time errors during a build, the error will be highlighted and an editor will be opened to the source file that the error occurred in. If there are any runtime errors while your program is running or being debugged, they will also show up in the build window.
Double clicking on an error line will open an editor to the selected source file.
You may increase the amount of debug output shown in this window by adjusting the Debug Level option in the IDE Configuration (see IDE Configuration).
Right clicking on the build output will allow you to clear or save the output to a file.