Gnote 3.10.x fails to build on several archs supported in Debian (ia64, powerpc, s390, sparc), but builds fine on common archs like i386 and amd64. Tail of build log for all those build failures is the same:

notewindow.cpp: In member function 'void gnote::NoteWindow::enabled(bool)':
notewindow.cpp:626:5: error: invalid initialization of reference of type 'Glib::RefPtr<Gtk::Action>&' from expression of type 'const Glib::RefPtr<Gtk::Action>'

You can find the full build logs at: https://buildd.debian.org/status/package.php?p=gnote

ia64: https://buildd.debian.org/status/fetch.php?pkg=gnote&arch=ia64&ver=3.10.0-1&stamp=1382547717
powerpc: https://buildd.debian.org/status/fetch.php?pkg=gnote&arch=powerpc&ver=3.10.0-1&stamp=1382521225
s390: https://buildd.debian.org/status/fetch.php?pkg=gnote&arch=s390x&ver=3.10.0-1&stamp=1382564019
sparc: https://buildd.debian.org/status/fetch.php?pkg=gnote&arch=sparc&ver=3.10.0-1&stamp=1382542461

I'm not sure if this is a bug in gnote, or some other component like glib. Also, FWIW, gnote 3.8.x built fine on all archs supported in Debian (including the currently troublesome ones).