Lars Ingebrigtsen writes: > Does setting (setq debug-on-error t) give you a backtrace for these > errors? No, but I just made one happen by removing the internal_condition_case_1 wrapper on the read_process_output_call in read_and_dispose_of_process_output. Then after I got the first backtrace showing that the error was in term-emulate-terminal I eval-defun'd it to make a more useful backtrace: