To simplify creation of bug reports, and to allow better tracking of
reports, we use the GNATS bug tracking system. Part of that system is
the gccbug script. This is a Unix shell script, so you need a
shell to run it. It is normally installed in the same directory where
gcc is installed.
The gccbug script is derived from send-pr, see Creating new Problem Reports. When invoked, it starts a text editor so you can fill out the various fields of the report. When the you quit the editor, the report is automatically send to the bug reporting address.
A number of fields in this bug report form are specific to GCC, and are explained at http://gcc.gnu.org/gnats.html.