/usr/bin/gqrx:11:xcb_setup_vendor_end:xcb_setup_pixmap_formats:find_format_by_depth:xcb_image_native:xcb_image_shm_put

The Ubuntu Error Tracker has been receiving reports about a problem regarding gqrx-sdr. This problem was most recently seen with package version 2.6-gqrx2~xenial, the problem page at https://errors.ubuntu.com/problem/5f9043c2c6a65c12167887a84678553d87713670 contains more details, including versions of packages affected, stacktrace or traceback, and individual crash reports.
If you do not have access to the Ubuntu Error Tracker you can request it at http://forms.canonical.com/reports/.