Please see discussion at https://github.com/anholt/libepoxy/issues/148 regarding a recent breakage between QEMU and the nvidia driver. The gist seems to be that commit 86c0522c63e84ee9a98b9cd9cf6588faba1bac23 introduces mechanisms that check for EGL extensions at build time instead of runtime. nvidia does not provide the requested extension, resulting in a crash when the Spice window is loaded. Thanks Jeff