error: unhandled error reached main: error.A
error return trace (most recent call last):
  frame 0: <location pending DWARF> (raw 1)
  frame 1: <location pending DWARF> (raw 1)
  frame 2: <location pending DWARF> (raw 1)
  frame 3: <location pending DWARF> (raw 1)
  frame 4: <location pending DWARF> (raw 1)
  frame 5: <location pending DWARF> (raw 1)