Install the gtk-3 development headers first. On Debian, this can be done using:
apt-get install libgtk-3-dev

We are using [meson](http://mesonbuild.com/) as a build system, you can build with

    meson build/
    ninja -C build/

Since version 3 of gtk# a profiler called "gui-thread-check" is included as
part of the install for debugging purposes. (It's located in the subfolder
gtk/gui-thread-check .)

This profiler module can be used to check if a GTK# application is trying to
invoke gtk or gdk methods from a thread which is not the main GUI thread.

To use it, run your application with the command:

    mono --profile=gui-thread-check yourapp.exe

If the profiler is properly installed, you'll see an output like this:

    *** Running with gui-thread-check ***
    *** GUI THREAD INITIALIZED: 2861676352

While the application is running, if the profiler detects a non-gui thread
invoking gtk methods, it will print a warning message together with a
stack trace. For example:

    *** GTK CALL NOT IN GUI THREAD: Widget.gtk_widget_get_parent
       Widget.get_Parent
       SourceEditorWidget.SetLastActiveEditor
       SourceEditorWidget.get_TextEditor
       SourceEditorWidget.get_Document
       SourceEditorWidget.HandleParseInformationUpdaterWorkerThreadDoWork
       BackgroundWorker.OnDoWork
       BackgroundWorker.ProcessWorker

A mailing list for Gtk# discussion is available.

You can subscribe to the mailing list by visiting:

    http://lists.ximian.com/mailman/listinfo/gtk-sharp-list

And following the instructions (on that page) to subscribe.
Messages are posted on this mailing list by sending them to:

    gtk-sharp-list@ximian.com

(The mailing list requires you to subscribe in order to post
messages.)

An archive of this mailing list can be found at:

    http://lists.ximian.com/archives/public/gtk-sharp-list/

Also, people can get help with and discuss Gtk# on IRC via the
#gtk# or #mono channels on the irc.gnome.org IRC server.

People looking for general help with C# should visit the
#c# channel on irc.freenode.net IRC server.

For developers wishing to "get started" with Gtk#, they are encouraged
to read the Mono Hand Book:

    http://www.mono-project.com/docs/gui/gtksharp/

For those who wish to help with the development of Gtk#, they should
read the file named: HACKING.

Also, anyone wishing to hack Gtk# is encouraged to join the Gtk#
mailing list. And to visit the #gtk# IRC channel (on irc.gnome.org).