Cannot launch monogame pipeline tool on Ubuntu 14.04

If I click the icon in my system menu I get a spinning wheel and then nothing. If I try to launch it from my command line I get this:

[WARNING] Function not found: gtk_get_locale_direction
[WARNING] Function not found: gtk_normalise_detailed_action_name
[WARNING] Function not found: gtk_show_uri_on_window
[WARNING] Function not found: gtk_application_get_accels_for_action
[WARNING] Function not found: gtk_application_get_actions_for_accel
[WARNING] Function not found: gtk_application_get_menu_by_id
[WARNING] Function not found: gtk_application_list_action_descriptions
[WARNING] Function not found: gtk_application_prefers_app_menu
[WARNING] Function not found: gtk_application_set_accels_for_action
[WARNING] Function not found: g_application_get_resource_base_path
[WARNING] Function not found: g_application_set_resource_base_path
[WARNING] Function not found: g_application_get_is_busy
[WARNING] Function not found: g_application_bind_busy_property
[WARNING] Function not found: g_application_unbind_busy_property

Unhandled Exception:
System.EntryPointNotFoundException: gtk_application_prefers_app_menu
at (wrapper managed-to-native) Eto.GtkSharp.NativeMethods+NMLinux.gtk_application_prefers_app_menu(intptr)
at Eto.GtkSharp.NativeMethods.gtk_application_prefers_app_menu (System.IntPtr application) [0x0000c] in <3bbc1daff97142648cd48237c49932b3>:0
at Eto.GtkSharp.Forms.ApplicationHandler.Initialize () [0x0004e] in <3bbc1daff97142648cd48237c49932b3>:0
at Eto.WidgetHandler1[TWidget].Eto.Widget.IHandler.Initialize () [0x00000] in <6db481985cca4510b36c8dbd12852b82>:0 at Eto.Widget.Initialize () [0x0000a] in <6db481985cca4510b36c8dbd12852b82>:0 at Eto.Widget..ctor () [0x00099] in <6db481985cca4510b36c8dbd12852b82>:0 at Eto.Forms.Application..ctor (Eto.Forms.Application+InitHelper init) [0x0000b] in <6db481985cca4510b36c8dbd12852b82>:0 at Eto.Forms.Application..ctor (Eto.Platform platform) [0x00007] in <6db481985cca4510b36c8dbd12852b82>:0 at MonoGame.Tools.Pipeline.Program.Main (System.String[] args) [0x0000a] in <508144dba4344cc0bb440820f25e3eca>:0 [ERROR] FATAL UNHANDLED EXCEPTION: System.EntryPointNotFoundException: gtk_application_prefers_app_menu at (wrapper managed-to-native) Eto.GtkSharp.NativeMethods+NMLinux.gtk_application_prefers_app_menu(intptr) at Eto.GtkSharp.NativeMethods.gtk_application_prefers_app_menu (System.IntPtr application) [0x0000c] in <3bbc1daff97142648cd48237c49932b3>:0 at Eto.GtkSharp.Forms.ApplicationHandler.Initialize () [0x0004e] in <3bbc1daff97142648cd48237c49932b3>:0 at Eto.WidgetHandler1[TWidget].Eto.Widget.IHandler.Initialize () [0x00000] in <6db481985cca4510b36c8dbd12852b82>:0
at Eto.Widget.Initialize () [0x0000a] in <6db481985cca4510b36c8dbd12852b82>:0
at Eto.Widget…ctor () [0x00099] in <6db481985cca4510b36c8dbd12852b82>:0
at Eto.Forms.Application…ctor (Eto.Forms.Application+InitHelper init) [0x0000b] in <6db481985cca4510b36c8dbd12852b82>:0
at Eto.Forms.Application…ctor (Eto.Platform platform) [0x00007] in <6db481985cca4510b36c8dbd12852b82>:0
at MonoGame.Tools.Pipeline.Program.Main (System.String[] args) [0x0000a] in <508144dba4344cc0bb440820f25e3eca>:0

You need Gtk 3.14 or newer to run the Pipeline Tool, Ubuntu 14.04 has Gtk 3.12 by default if I remember correctly.