[HN Gopher] Bug #915: Solved
___________________________________________________________________
Bug #915: Solved
Author : ingve
Score : 72 points
Date : 2020-01-14 21:45 UTC (1 hours ago)
(HTM) web link (nedbatchelder.com)
(TXT) w3m dump (nedbatchelder.com)
| hinkley wrote:
| The first really bizarre bug I fixed was a file descriptor bug.
| The code was streaming data and in some cases the app would just
| stop processing network packets. He or I figured out that
| keyboard input would temporarily unblock things.
|
| He had a compound conditional without enough parentheses in it,
| and one of the possible outcomes resulted in fd=1, which is stdin
| on many operating systems. My general advice now is to assume a
| 5th grade reading level for math (which consists of +-x/), and
| use parentheses for _everything_ else. Especially if you think
| yourself to be clever (narrator: he did).
| lilSebastian wrote:
| Previously: https://news.ycombinator.com/item?id=22028581
| egdod wrote:
| That was quick.
| yhoiseth wrote:
| This made me laugh out loud:
|
| > Hacker News can be helpful, in spite of the tangents about
| shell redirection, authorship attribution, and GitHub
| monoculture.
| alpb wrote:
| Pretty funny how the entire HN rallied together to solve some
| github issue on someone's personal repo. I'll try posting some of
| my bugs here to see if it'll work for me as well.
| jnwatson wrote:
| It is hardly just "someone's personal repo". coveragepy has 1k
| github stars and is used by nearly every Python project under
| the sun.
| AdmiralAsshat wrote:
| Soon: "Hacker News Code Review As A Service"
| dang wrote:
| There's a power-law dropoff when it comes to follow-up
| submissions, since the hivemind craves novelty. But it would be
| fun to try. Maybe it could become a thing: Bug HN!
|
| The trick would be to make the bugs intrinsically interesting:
| weird or hard, and preferably both.
| ehsankia wrote:
| To be fair, it was a great nerd snipe, as it was a mysterious
| bug that happened when things aligned perfectly, yet still had
| a very good repro making it easy to test.
| kjksf wrote:
| This bug, the HN thread and how hard it is to fix
| (https://bugs.python.org/issue39318) is a pretty good argument
| against exceptions.
|
| A code that looks simple and correct has been hiding a very
| subtle bug because no one understood the implications of an
| arbitrary exception being thrown at any point under the caller.
|
| And of all the people who looked at the bug not a single one
| looked at this seemingly simple code and said "oh yeah, that's
| because this code is obviously wrong". It took someone skilled
| enough to script gdb to figure out the buggy interactions.
|
| So the next time someone makes fun of `if err != nil`, send them
| the buggy implementation of tempfile.NamedTemporaryFile and ask
| them to spot the bug.
|
| Also, KeyboardInterrupt should not be an exception. It's a
| signal, not an error or exceptional situation that code wants to
| report to the caller. But once you have a hammer, everything
| looks like like a nail. In addition to making the code impossible
| to reason about, no-one can agree what exactly is an exception so
| they randomly commingle expected errors with exceptional
| circumstances and, in case of Python, out-of-band signals.
|
| ("randomly" as in: why is "open file" throwing an exception when
| file doesn't exist but "find substring" returns -1 when substring
| doesn't exist?)
| excpointer wrote:
| Popcorn time...
| 0xff00ffee wrote:
| I saw this pop up a few days ago. Can someone ELI5 how this
| person's bug made it to the top of HN?
| ehsankia wrote:
| So the final answer is basically, there's nothing the author can
| do. The problem was half with the user's code mocking with
| internals, and half with downstream library not cleaning up
| properly.
___________________________________________________________________
(page generated 2020-01-14 23:00 UTC)