Same as "synopsis". Fix: Apply patches where "guint" changes to GtkType, as recommended by docs of GTK. Patch attached with submission follows: How-To-Repeat: Install from port or package on 64-bit machine, and run.
A commit references this bug: Author: marino Date: Sun Jun 15 13:10:22 UTC 2014 New revision: 357879 URL: http://svnweb.freebsd.org/changeset/ports/357879 Log: graphics/cinepaint: Fix start-up segfault on amd64 PR: 183691 Submitted by: avjwork (gmail) Changes: head/graphics/cinepaint/Makefile head/graphics/cinepaint/files/patch-app_brush.c head/graphics/cinepaint/files/patch-app_brushgenerated.h head/graphics/cinepaint/files/patch-app_channel.h head/graphics/cinepaint/files/patch-app_depth_brushgenerated.c head/graphics/cinepaint/files/patch-app_depth_channel.c head/graphics/cinepaint/files/patch-app_depth_layer.c head/graphics/cinepaint/files/patch-app_drawable.c head/graphics/cinepaint/files/patch-app_drawable.h head/graphics/cinepaint/files/patch-app_layer.h head/graphics/cinepaint/files/patch-lib_chainbutton.c head/graphics/cinepaint/files/patch-lib_pixmap.c head/graphics/cinepaint/files/patch-lib_size_entry.c head/graphics/cinepaint/files/patch-plug-ins_script-fu_gimpcolorbutton.c
Thanks!