In some cases, it can happen that crashlogs don't have any signal in the exception, which causes the parser to crash. This fixes the parsing by checking if the `signal` field is in the `exception` dictionary before trying to access it. rdar://84552251 Differential Revision: https://reviews.llvm.org/D119504 Signed-off-by: Med Ismail Bennani <medismail.bennani@gmail.com>