Created attachment 371644 [details]
gtk_application_ex.pl

The "open" signal is emitted, either by the "open with" menu option in a file manager, or by supplying file names on the command line, or via gdbus. Attached is a minimal perl script, running it with a filename as an argument, e.g.:

perl gtk_application_ex.pl file.name

should open a window and then report the signals emitted in the terminal window:

starting with file.name
Hello world!
running activate
files: file.name
Goodbye world!

Unforunately, the open signal is never emitted, and so the files: line is not printed. A python version of the same script is also attached. This works as expected.