• Treczoks@lemmy.world
    12·
    2 months ago

    Heisenbug. Nasty buggers, especially in my domain: Embedded Engineering. When you are in the debugger, the whole processor is stopped, missing tons of data coming in, missing interrupts, getting network timeouts, etc. More often than not, resuming makes no sense, and you have to get straight to reboot.

      • Treczoks@lemmy.world
        1·
        2 months ago

        That’s why I work with an extraordinary diligence to avoid making errors from the very start. Debugging is only a measure of last resort.

    • Lupec@lemm.ee
      28·
      2 months ago

      Lol my workplace ships Angular in debug mode. Don’t worry though, the whole page kills itself if a dubious third-party library detects the console is open. Very secure and not brittle at all! Please send help

        • SteveTech@programming.devEnglish
          5·
          2 months ago

          I’ve seen some that activate an insane number of breakpoints, so that the page freezes when the dev tools open. Although Firefox let’s you disable breaking on breakpoints all together, so it only really stops those that don’t know what they’re doing.

      • Barbarian@sh.itjust.works
        12·
        2 months ago

        Blink-blink-blink. Blink. Blink. Blink. Blink-blink-blink.

        No, I don’t have something in my eyes, I swear I’m fine looks nervously at boss.

    • MultipleAnimals@sopuli.xyz
      25·
      2 months ago

      You can imagine how many node projects there are running in production with npm run. I have encountered js/ts/node devs that don’t even know that you should like, build your project, with npm build and then ship and serve the bundle.

  • Quacksalber@sh.itjust.works
    157·
    2 months ago

    Aren’t those almost always race condition bugs? The debugger slows execution, so the bug won’t appear when debugging.

    • BlueKey@fedia.ioOP
      852·
      2 months ago

      Turned out that the bug ocurred randomly. The first tries I just had the “luck” that it only happened when the breakpoints were on.
      Fixed it by now btw.

      • Skullgrid@lemmy.world
        951·
        2 months ago

        bug ocurred randomly.

        Fixed it by now btw.

        someone’s not sharing the actual root cause.

        • BlueKey@fedia.ioOP
          60·
          2 months ago

          I’m new to Go and wanted to copy some text-data from a stream into the outputstream of the HTTP response. I was copying the data to and from a []byte with a single Read() and Write() call and expexted everything to be copied as the buffer is always the size of the while data. Turns out Read() sometimes fills the whole buffer and sometimes don’t.
          Now I’m using io.Copy().

          • dfyx@lemmy.helios42.de
            51·
            2 months ago

            Note that this isn’t specific to Go. Reading from stream-like data, be it TCP connections, files or whatever always comes with the risk that not all data is present in the local buffer yet. The vast majority of read operations returns the number of bytes that could be read and you should call them in a loop. Same of write operations actually, if you’re writing to a stream-like object as the write buffers may be smaller than what you’re trying to write.

            • xthexder@l.sw0.com
              3·
              2 months ago

              Ah yes… several years ago now I was working on a tool called Toxiproxy that (among other things) could slice up the stream chunks into many random small pieces before forwarding them along. It turned out to be very useful for testing applications for this kind of bug.

            • bl_r@lemmy.dbzer0.com
              13·
              2 months ago

              I’ve run into the same problem with an API server I wrote in rust. I noticed this bug 5 minutes before a demo and panicked, but fixed it with a 1 second sleep. Eventually, I implemented a more permanent fix by changing the simplistic io calls to ones better designed for streams

      • dunz@feddit.nu
        17·
        2 months ago

        I had a bug like that today . A system showed 404, but about 50% of the time. Turns out I had two vhosts with the same name, and it hit them roughly evenly 😃

        • vortexsurfer@lemmy.world
          2·
          2 months ago

          Had a similar thing at work not long ago.

          A newly deployed version of a component in our system was only partially working, and the failures seemed to be random. It’s a distributed system, so the error could be in many places. After reading the logs for a while I realized that only some messages were coming through (via a message queue) to this component, which made no sense. The old version (on a different server) had been stopped, I had verified it myself days earlier.

          Turns out that the server with the old version had been rebooted in the meantime, therefore the old component had started running again, and was listening to the same message queue! So it was fairly random which one actually received each message in the queue 😂

          Problem solved by stopping the old container again and removing it completely so it wouldn’t start again at the next boot.

      • xthexder@l.sw0.com
        2·
        2 months ago

        And that’s where Release with debug symbols comes in. Definitely harder to track down what’s going on when it skips 10 lines of code in one step though. Usually my code ends up the other way though, because debug mode has extra assertions to catch things like uninitialized memory or access-after-free (I think specifically MSVC sets memory to 0xcdcdcdcd on free in debug mode).

    • ExtraMedicated@lemmy.worldEnglish
      12·
      2 months ago

      I had one years ago with internet explorer that ended up being because “console.log” was not defined in that browser unless you had the console window open. That was fun to troublshoot.

  • Nighed@sffa.communityEnglish
    51·
    2 months ago

    Someone has a compiler if statement left somewhere in their code (… probably)

      • leisesprecher@feddit.org
        36·
        2 months ago

        One of our customers does that. It happened multiple times already that one dev fixed an issue in production, and the next regular deployment overwrote everything.

        But fortunately, it’s just critical infrastructure and nothing important.

        • henfredemars@infosec.pubEnglish
          13·
          2 months ago

          When I left my last job they were using the zip file method for version control and one creative developer managed to link two versions of libc at the same time.

          Software is so useful that the standard for utility is extremely low.

  • Aceticon@lemmy.world
    47·
    2 months ago

    Sound like a critical race condition or bad memory access (this latter only in languages with pointers).

    Since it’s HTTP(S) and judging by the average developer experience in the domain of multi-threading I’ve seen even for people doing stuff that naturally tends to involve multiple threads (such as networked access by multiple simultaneous clients), my bet is the former.

    PS: Yeah, I know it’s a joke, but I made the serious point anyways because it might be useful for somebody.

  • answersplease77@lemmy.world
    4·
    2 months ago

    this happens with so many scripts I’ve tried to debug with strace because strace requires to run as root or sudo which elevates the niceness of process which prevents certain errors from occuring when the script is run with root permissions and so it runs flawlessly without bugs and you sit wondering wtf