so... I've been tinkering with KVM again. my desktop is windows, the linux server is remote, so I have a ssh X tunnel running, and XMing running locally, and launch virt-manager. opens fine, shows the VM I created some time ago. I select that VM (which is running centos 6), and 'open', a window opens for a few seconds, then blam, virt-manager exits before I can click on the 'details' lightbulb. if I run virt-manager --debug, I get the following output after clicking on 'open'... 2015-10-22 16:08:36,377 (engine:471): window counter incremented to 2 2015-10-22 16:08:36,379 (console:1150): Starting connect process for proto=vnc trans=None connhost=localhost connuser=None connport=None gaddr=127.0.0.1 gport=5900 gsocket=None 2015-10-22 16:08:36,381 (console:378): VNC connecting to localhost:5900 2015-10-22 16:08:37,009 (console:1061): Viewer connected [xcb] Extra reply data still left in queue [xcb] This is most likely caused by a broken X extension library [xcb] Aborting, sorry about that. python: xcb_io.c:576: _XReply: Assertion `!xcb_xlib_extra_reply_data_left' failed. Aborted (core dumped) -- john r pierce, recycling bits in santa cruz