Debugging the front-end protocol

When setting the FGLGUIDEBUG environment variable to 1, information about GUI communication will be printed to stderr by the runtime system, and the GUI protocol exchange will be indented for a better readability in the front-end log window.

UNIX™ (shell) example:

$ FGLGUIDEBUG=1
$ export FGLGUIDEBUG
$ fglrun myprog 2>guidbg.txt

Note that in TUI mode, displayed screens can be dumped by setting the DBSCREENDUMP or DBSCREENOUT environment variables. This can be used to take a snapshot of the current TUI screen, for debugging or testing purpose.