khal v0.9.7 comes with two fixes (no more crashing on datetime events with UNTIL properties and no more crashes on search finding events with overwritten subevents) and one change: search will now print subevents of matching events once, i.e., that is one line for the master event, and one line for every different overwritten event.
Get khal v0.9.7 from this site, or from pypi.