the bug i encountered is discussed here. https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=839356 The patch that resolves the issue is at https://anonscm.debian.org/cgit/collab-maint/mysql-workbench.git/plain/debian/patches/gtk.patch?id=2d345f9
I can confirm this bug: cat /var/tmp/portage/dev-db/mysql-workbench-6.3.4-r2/temp/build.log |grep error: /var/tmp/portage/dev-db/mysql-workbench-6.3.4-r2/work/mysql-workbench-community-6.3.4-src/library/forms/gtk/src/lf_popover.cpp:383:13: error: no match for ‘operator!=’ (operand types are ‘Glib::RefPtr<Gdk::Window>’ and ‘int’) /var/tmp/portage/dev-db/mysql-workbench-6.3.4-r2/work/mysql-workbench-community-6.3.4-src/library/forms/gtk/src/lf_popover.cpp:399:13: error: no match for ‘operator!=’ (operand types are ‘Glib::RefPtr<Gdk::Display>’ and ‘int’)
I can also confirm it; there are numerous errors about variables having data types for which no conversion operator is known but required to compare them.
*** Bug 601938 has been marked as a duplicate of this bug. ***
This patch has now been applied to mysql-workbench-5.3.4-r2
*** Bug 619524 has been marked as a duplicate of this bug. ***