#0  icaltimezone_get_utc_offset (zone=0x1, tt=0x7ffd708df390, is_daylight=0x0) at ./src/libical/icaltimezone.c:841
  [Error: icaltimezone.c was not found in source tree]
#1  0x00007feb6b69687d in icaltimezone_convert_time (tt=tt@entry=0x7ffd708df390, from_zone=from_zone@entry=0x1, to_zone=to_zone@entry=0x7feb6b8c4420 <utc_timezone>) at ./src/libical/icaltimezone.c:808
  [Error: icaltimezone.c was not found in source tree]
#2  0x00007feb6b69286f in icaltime_convert_to_zone (tt=..., zone=0x7feb6b8c4420 <utc_timezone>) at ./src/libical/icaltime.c:981
  [Error: icaltime.c was not found in source tree]
#3  0x00007feb6b692a84 in icaltime_compare (a_in=..., b_in=...) at ./src/libical/icaltime.c:737
  [Error: icaltime.c was not found in source tree]
#4  0x00007feb6b8ffcec in cal_obj_remove_duplicates_and_invalid_dates (occs=<optimized out>) at ./src/calendar/libecal/e-cal-recur.c:2712
  [Error: e-cal-recur.c was not found in source tree]
#5  cal_obj_expand_recurrence (event_start=0x0, zone=0x7ffd708e03c0, recur=0x0, interval_start=0x1, interval_end=0xc0000001b, finished=0x7ffd708e03f0) at ./src/calendar/libecal/e-cal-recur.c:2299
  [Error: e-cal-recur.c was not found in source tree]
#6  0x00007feb6b127f74 in ?? () from /tmp/apport_sandbox_e9RZZx/usr/lib/x86_64-linux-gnu/libgio-2.0.so.0
#7  0x7f7f7f7f7f7f7f7f in ?? ()
#8  0x000055b1e56d44a0 in ?? ()
#9  0x00000000000005a0 in ?? ()
#10 0x0000000000000b80 in ?? ()
#11 0x000000000000002d in ?? ()
#12 0x0000005d00000011 in ?? ()
#13 0x000000000000000f in ?? ()
#14 0x0000000000000101 in ?? ()
#15 0x0000000000000110 in ?? ()
#16 0x0000000000000000 in ?? ()