If the quick panel text is empty it segfaults:

Program received signal SIGSEGV, Segmentation fault. 0x00000000005ea10a in int fuzzy_match_string_impl<case_sens_cmp>(const_substring, const_substring, const_substring, unsigned int, case_sens_cmp) ()

This only happens if I type in something such that the list becomes empty(nothing matches) then press backspace

minimal trigger, in the console type:

window.show_quick_panel(""], lambda: None)

Thanks for the report, will fix for the next build