pipeline random crash when failed to negotiate with glimagesink.

The pipeline

gst-launch-1.0 videotestsrc num-buffers=30 ! capsfilter caps=video/x-raw,format=P010_10LE,width=480,height=320 ! vaapipostproc format=bgr10a2-le ! glimagesink

random crash. The negotiate will fail, which is expected, but the crash is unexpected.

with setting the debug level to

export GST_DEBUG=*:INFO

The crash is easy to duplocate