Message 132550 - Python tracker

Remainder for me: the patch contains some whitespace changes in Makefile.pre.in and Setup.dist.

dump_traceback(), enable(), dump_tracebacks_later(), register() flush the input file. It is not said in the doc. Should it be documented? For enable(), dump_tracebacks_later(), register(), it may be useless because the traceback is dumped later, and there may be new buffered data in the file. But I don't think that it hurts to flush the file.