15 ms·

Ask HN: What is the funniest bug you encountered?

53 points by BuenosAir 9y ago

mtmail 9y ago
A cluster of 10+ machines was processing data for a whole week (7 days). Think Hadoop with counting and grouping numbers. The output was slightly over 2GB. The user specified his home directory as output. The home directory was NFS-mounted and didn't support files over 2GB, thus no file was written and the job had to be rerun.
- malux85 9y ago
  There’s a similar right of passage for Deep Learning engineers using python and Keras - every single one of us has been burned by waiting for a week for a model to train, only to find “h5py” is not installed, exception is thrown and all work lost. (That’s the python module used for persistence of the model weights) Then the young grasshoppers learn about checkpointing and using our dev ops systems to make sure the environment is up to spec, but I feel this has to happen at least once to each Deep Learning researcher
  - shashwat986 9y ago
    Something very similar happened to me. To this day, I don't run any python script without the `-i` flag
JimDabell 9y ago
One amusing one springs to mind: an image thumbnailer on a website for a very popular all-girl band. It was "smart" and cropped images to the right aspect ratio based on entropy in the image. In practice, this manifested itself as a foot fetish – if a photo included feet, it would centre the thumbnail on the feet almost every time. The gallery index pages looked quite odd.
- cphoover 9y ago
  I built a similar tool early in my career, only it used facial detection with haar cascade classifiers. It was kinda poorly written in PHP but it worked!
protomyth 9y ago
Tester worked a later shift (noon to 8pm) and was running scenarios. Got a really odd error that made contracted pricing incorrect. Developer came in the next morning and ran the scenario just fine. Tester repeated the scenario at 6:30PM and got the same error. Both thought the other was nuts and this went on for a week. Found out it was an interaction issue when using the time (UDT) to get the current market date. Lesson: if anything goes wrong at night but not during the morning, look at all the date code.
- rmetzler 9y ago
  I also found a test breaking on Mondays. Never on any other day. It tested a sum for the current week but made the mistake of creating models for "yesterday" which is on another week if it's the first day of the week (depending on location, Monday in Europe, Sunday in the USA).
  - martinpw 9y ago
    Had an office where, every Thursday, one developer's machine would reboot at the same time late in the evening. It didn't happen to anyone else. Eventually he decided to stay late one Thursday and watch it to see what happened. At the appointed time the cleaner came by, unplugged his machine from the power socket and plugged in the vacuum cleaner to clean the room, and when done, plugged the machine back in.
    - dvtv75 9y ago
      Some decades ago, friends of mine ran an ISP that resold bandwidth from another business. They used a leased line to the business, and every Friday evening at about 7.30 their connection dropped out. It turned out that the cleaners at the remote end would plug their vacuum cleaner into the same circuit that was powering my friends' hardware. The power surge caused their hardware to crash, and nobody had access to properly reboot it until Monday 8.30am.
    - staikken 9y ago
      Heard a similar story about a laboratory system with tight environmental controls. Every so often the humidity would spike and the room would go out of tolerance after typical work hours. The designers of the system were under quite a bit of pressure until someone finally stuck around long enough to catch the janitor mopping the floors.
rlarkins 9y ago
Reset line for an embedded device coupling onto another line, error caused by noise on line was detected and handled in the debounce time for the reset line. Caused reset reason to report as an error even during normal resets.
noir_lord 9y ago
When I was young I wrote a system that had an error message that was "I'm sorry Dave, I'm afraid I can't do that" for a small local business (back in the 90's). 6mths after it was in production I got an email saying "The system won't work and it keeps calling me Dave!, I'm not called Dave, my name is Chris!". Lesson learnt right there, never put funny error messages in with the intention of replacing them later and never swear in error messages.
turc1656 9y ago
"ERROR: Task completed successfully"
- deeteecee 9y ago
  you got my vote for funniest here so far :)
- grkvlt 9y ago
  This is actually really common. I can't remember if it's Linux or Windows specific, but it is almost always caused by code like this: result = some_system_call(argv); if (result == ERROR) { do_something_else(); error_message = get_text_for_last_error(); display("ERROR: " + error_message); } What happens is that the call to `do_something_else()` calls another system call, which completes successfully. Unfortunately, system calls just return a success or failure code, and store the actual detailed error number in a shared global variable. So, when the handler code goes to retrieve the text message describing the error, it ends up looking up the code for the status of the second system call. But when that returned it saved the code for 'Task completed successfully' over the first error code the developer actually wanted... I think it's probably Windows, maybe the `perror()` call, that does this?
kolbe 9y ago
A finance quant created a strategy with amazing results. He discovered the theory, tested it, refined it, and set up a presentation to the portfolio manager to start running it. problem was that he inverted PnL, and had spent the previous couple weeks figuring out how to maximize losses. INBF "do the opposite." Markets don't work that way.
- jerf 9y ago
  What Silicon Valley startup did he land in after he was fired?
pwason 9y ago
Not really a bug, but.. An early release of our product (not to be named), contained a database that contained a perl script that was written out to a web server. The person who took over maintaining this script looked at the original author's code and put a comment line in containing the descriptive phrase "Chicken Goat Fuck Logic" (aka "CGF Logic"). We accidentally forgot to remove that comment before producing the "gold" CD. A couple of weeks later, a very large national youth organization (also not to be named) contacted us, saying they would be unable to use our software, because their CyberNanny software had detected swear words in the output. Arguably, if this hadn't happened, we would have become Amazon before Amazon became Amazon. Ooops!
- metalliqaz 9y ago
  why not named?
- amatecha 9y ago
  Rather humorously, it appears the person who wrote the script created this website to commemorate the birth of CGF Logic : http://chickengoatfuck.com/ http://chickengoatfuck.com/
billconan 9y ago
I had this bug that can reproduce only on a specific hp notebook, after running certain stress test for days. The issue (a crash) was in a device driver we were developing, but the root cause was because 1 single bit in the host memory was flipped randomly. My coworker joked that this bug was due to strong sunspot activities during those days (We indeed saw news about strong sunspot activities at the time.), so that strong universal radiation altered the data on the memory. I guess that batch of memory the notebook used had some issues. My background is purely software, I always thought that computer hardware is rigid and trustworthy. But I learnt from this bug that it's not always the case.
- jeanmichelx 9y ago
  That's what we want you to think, but the hardware is at least as much of a mess as the software
  - Toast_25 9y ago
    Any sufficiently advanced technology is indistinguishable from chaos. Oh, wait, those were regexes.
- aidos 9y ago
  I had a similar one (almost 20 years ago!) where I came back from lunch to a panic about all the sites being down. The errors on all the sites were reporting a broken sql query - something like "select * from qccounts...". I guess the way ASP worked meant that the code was stored in a common location in memory for all the sites. I like to imagine some cosmic event millions of years ago flipped that bit...
AnimalMuppet 9y ago
An embedded system written in C++ had a Singleton. The Singleton pattern means that you have one instance, which has to live somewhere. This implementation had the instance as a static variable in the getInstance() method, e.g.: Foo* getInstance() { static Foo; return foo; } This is perfectly valid. Unfortunately, getInstance() was implemented in Foo.h, not in Foo.cpp. But in C++, functions in header files are inline by default. This means that every caller of Foo::getInstance() wound up with their own "static Foo" in their own inlined Foo::getInstance(), which meant that each caller got a different instance of the Singleton. Most interesting bug I've seen in ten years.
- tgb 9y ago
  Love the bug and it's been a while since I've done anything in C++, but isn't your description slightly wrong? There would be one instance per .cpp file that #include'd Foo.h, not one per getInstance() call. I don't think that "inline by default" is an accurate description of what would happen, and I have to imagine that if inline-ing a function caused different behavior, then that would be considered a compiler bug. Rather, I assume you mean it was "inlined" into the file at the #include point (and not once per call). Not that any of that changes the bug qualitatively.
  - AnimalMuppet 9y ago
    No, inlining replaces it at the place of call. Every call, even if there's multiple of them in the same file. The idea is that, by putting the implementation in the .h file, you're signaling that you don't want to pay the overhead of the function call. (Same thing with the "inline" keyword.) Now, if your function is sufficiently complicated, the compiler may choose to not inline it anyway (with the definition of "sufficient" being compiler-dependent). It could be considered a compiler bug that a function with a static variable in the body could be inlined. As you say, that changes the behavior of the function. Or perhaps it could be considered a specification error - I don't know if the standard prohibits inlining in this circumstance, but perhaps it should.
    - 9y ago
jawns 9y ago
Ten years from now, A⍰ may look back on A⍰t and laugh, but for rA⍰ght now, there A⍰s nothA⍰ng funny about A⍰t!
mooseburger 9y ago
One I wrote myself. Frustrated with some bizarre bug that I struggled to reproduce, I added two popups, to two separate conditionals that should have been exclusive (either one or the other executes, but never both). The first one said "What", and the second one "the fuck". I eventually managed to get both to show up, correctly forming the expletive, but it wasn't enough to help me solve the bug. There were more bugs though, had to get the ticket list down, so I dropped it and went after some lower-hanging fruit. A week later, our dev team gets sent a chain email with two screenshots, and a brief comment from the lead saying "This should never happen." In the first screenshot, was my "What" popup. I didn't need to see the second one. Turns out, when I moved on to other tickets, I completely forgot I had left that code just lying there, instead of discarding it, and had even pushed it with nary a thought. Nobody else on the dev team had seen either popup. No one in QA saw them either. And so, it made it all the way to production, where one of our users (mercifully, an in-house one), promptly caught it. The dept head thought I was committing sabotage, given the very specific set of actions one had to take to see the effect, but thankfully everyone knew that it was too stupid to do something like that via commit into repo! At the least, my frustration at the bug proved justified.
- JeanMarcS 9y ago
  A classic one ! Once I did the same one, just an echo in a php page. It was at the bottom of the page, after the footer. It was a job for a web designer I was helping. It's his son who saw it. So we removed it before the client (or anyone, it was in production) feedback to us. Bullet dodged !
spatley 9y ago
Keyboard not found Press F1 to continue
- AstralStorm 9y ago
  This one actually makes sense. You can connect a keyboard later or send the key code over remote interface or serial port.
swanson 9y ago
As an undergrad doing an internship helping some PhD students write a complex MATLAB simulation. Part of the simulation needed to be done in a loop and, naturally, I used "i" as the index variable. I spent several days debugging why the expected output result was not correct. Turns out there were some calculations using complex numbers (e.g. `x = 2 + 3*i`) and MATLAB decided that I obviously wanted to redefine the imaginary number constant in the loop. It was not very funny at the time.
troymc 9y ago
For some reason, in some astrodynamics calculations, I multiplied by r^2 rather than dividing, and since r was on the order of 10^8, the answer was off by 32 orders of magnitude. (Yes, I now know about changing the units so that the numbers aren't so big; this was before I understood all that.)
psyc 9y ago
Today I noticed that the longer my game ran, the faster all the animations ran. At first I thought I was imagining it. I had accidentally find/replaced the delta time since last frame with time since app start.
rdtsc 9y ago
> What is the funniest bug you encountered? Spiders. Customer put one of our server in a shack outside the main building. Spiders and other bugs got in the server causing the hardware to fail. We never never thought of testing our against an arachnid infestation.
FigBug 9y ago
It wasn't funny at the time. I helped develop and app + hardware for measuring the force generated when luge / ski cross / boarder cross athletes start. The handles measure the force and sent the data to an iPad which also recorded video. Worked fine in the office. Every time we went up on the mountain to test, the video didn't work. Go back to the hotel it worked fine. Whole project was going to fail because of this. Finally it worked once on the mountain, so we proved the system could work. Finally I found the bug. When setting the video orientation, I was passing in device orientation instead of UI orientation. In my office, I always have my iPad on a stand, so device orientation matched ui orientation and everything worked fine. When I was on the mountain, I held the iPad flat so I could shield it from the sun with my body, then I'd lift it up when the athlete was about to start. The video would fail to record if device orientation was 'down' since that isn't a valid orientation to rotate video. I only ended up finding it because I ended up leaving my iPad stand at home one day.
jpatokal 9y ago
A bug that occurred only on Wednesdays: https://gyrovague.com/2015/07/29/crashes-only-on-wednesdays/ https://gyrovague.com/2015/07/29/crashes-only-on-wednesdays/
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petedoyle 9y ago
I was in Rome a while back and wanted to go see Michelangelo's David. Searched for "David of Michelangelo" in Google Maps for Android. Clicked details. The main detail photo's aspect ratio is very tall and--because the photo is center-cropped--results in a zoomed in look right below his waist. :) Gave me a laugh. It's still live...
arthurjj 9y ago
tl;dr If you have an Enum don't have the 0 value be semantically meaningful. 2nd tl;dr If sex/gender is an Enum you should have at least 4 values unspecified, female, male, other. A few years ago I was working on a front end that talked to different scheduling software systems. Our front end had a much more nuanced way of representing sex/gender while the system that talked to scheduling systems had an older enum Bad_Gender { female = 0, male = 1, } A bug was introduced such that no gender was set. However the field not being set meant that it's value was 0. This led to all appointments being booked as women. Even a prostate exam. Needless to say we fixed the bug quickly.
petemc_ 9y ago
This isn't exactly side-splitting, but my home isp, virgin media uk, does dns hijacking for domains they cannot resolve. If you try to access http://bugzilla.anynonworkingdomain.com http://bugzilla.anynonworkingdomain.com for some reason it interprets that as a search for the term "porn". I have lots of tabs open to our bugzilla in work (where bugzilla.mycompany.com resolves correctly) so when I take laptop home, open it up and chrome refreshes tabs it looks like I have opened 20 tabs searching for porn. https://imgur.com/a/fyu0D https://imgur.com/a/fyu0D
- milesokeefe 9y ago
  Interesting, seems to only trigger when the search term contains the substring 'bugzilla' exactly: http://advancedsearch2.virginmedia.com/main?FailedURI=bugzilla http://advancedsearch2.virginmedia.com/main?FailedURI=bugzil...
lj3 9y ago
I once worked on a retail time management game. The doors of your store would open and then close when the customers came in. After a while, the doors would just start swinging open and closed all the time, like the store was being visited by a vengeful ghost. We never did figure out what caused that. This next bug (in the same game) we purposefully left in and it became an easter egg. A big part of the game was being able to customize your store with different retail stands and tables to put your merchandise on. If you edited your store layout while customers were in the store, you could trap them. The path finding code we wrote for the customers required a valid point of entry and a valid point of exit to the store. As soon as you trapped the customer, the lack of valid path to an exit had an unusual effect on the character animation. The character movement and animation speed would increase up to 2x, which made the customer look like it was freaking out. It also negatively effected the customer "happiness" state. A store's reputation score was based on the average customer happiness level over a particular time period. A trapped customer could absolutely destroy that score. I've seen it drop from 2000+ to 0 in seconds. As with the other bug, we never did figure out why this was happening.
giomasce 9y ago
Did not happen to me, but it's really baffling! https://www.ibiblio.org/harris/500milemail.html https://www.ibiblio.org/harris/500milemail.html
- bradknowles 9y ago
  I know Trey Harris. I remember when he first posted about this. I was the Sr. Internet Mail Administrator for AOL at the time, and I just about passed out from laughing so hard.
locopati 9y ago
While testing Adobe Pagemaker 5.5 for the Power Mac (a version built specifically to take advantage of the new Apple hardware), I discovered a specific set of steps that would overwrite video memory and turn the screen into the kind of static fuzz you'd see in a television tuned to no channel (back when that was possible).
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dragonwriter 9y ago
I once worked tech support in a Fortune 500 enterprise software company where I got a support call that traced back to a syntax error causing a crash in the Perl install script of our flagship product. Only “funny” because it's a phenomenally expensive product with on paper substantial QA/QC, and yet somehow it got into release with an install script that was guaranteed to fail.
vinchuco 9y ago
Accidental vertical farming on an old version of farmville caused by a race condition due to slow satellite internet speeds. You could take valid actions that would otherwise be mutually exclusive.
newtronic 9y ago
Back in the late 1980's, apple released a version of Unix called A/UX. In order to get excitement going about it, they sold Macintosh computers with A/UX preloaded to developers. The combo was cheaper than the equivalent Mac. So I bought two of them. I also bought the biggest displays for them; they weighted like 50 lbs. Probably 400 x 512; I don't remember. Anyway, I hooked both up to their displays and both booted to this message: When in Danger Or in Doubt Run in Circles Scream and Shout! Apple eventually admitted that A/UX didn't support those giant monitors. I installed Mac OS and it ran fine.
togusa2017 9y ago
Wrote a rate limiter in C. It broke when time got adjusted due to day light savings . Didn't take into account negative time delta. It was an ahuh moment when I realized the next day
- GFischer 9y ago
  Relevant XKCD: https://xkcd.com/1883/ https://xkcd.com/1883/ And yes, I do hate working with timezones - and so does everyone else I guess, Outlook still fails to correctly send appointment invites across timezones when DST is involved.
  - bradknowles 9y ago
    UTC FTW!
synicalx 9y ago
Not strictly an error or bug, but rather the cause of one. Back in my ISP days, we sold IPTV packages, which we in turn received from the IPTV company via satellite. And because of this elaborate distribution method we would get THE BEST outage/disruption notices. For example; "Urdu News will be unavailable from approximately 1AM GMT to 8PM, due to HIGH ENERGY SOLAR ACTIVITY." How much better is that than telling your customers "Your news is unavailable because Barry doesn't understand BGP"?!
vinchuco 9y ago
A different kind of bug https://www.npr.org/sections/krulwich/2013/06/19/193493225/the-love-that-dared-not-speak-its-name-of-a-beetle-for-a-beer-bottle https://www.npr.org/sections/krulwich/2013/06/19/193493225/t...
_nalply 9y ago
In a chemical simulation with OpenGL animation of molecules crashing into each other we used the wrong sign for the vectors after colliding. Instead moving in the opposite direction the molecules started to glue to each other. They kept moving around in ever growing chunks with wild psychedelic shapes. We kept this bug as an easter egg.
aaomidi 9y ago
So we have a channel in Telegram that mirrors hackernews... and this just happened so I guess it's a nice meta bug? https://i.imgur.com/JtbCGkB.png https://i.imgur.com/JtbCGkB.png (Disclaimer this doesn't happen, like ever)

53 points by BuenosAir 9y ago

A cluster of 10+ machines was processing data for a whole week (7 days). Think Hadoop with counting and grouping numbers. The output was slightly over 2GB. The user specified his home directory as output. The home directory was NFS-mounted and didn't support files over 2GB, thus no file was written and the job had to be rerun.

malux85 9y ago
There’s a similar right of passage for Deep Learning engineers using python and Keras - every single one of us has been burned by waiting for a week for a model to train, only to find “h5py” is not installed, exception is thrown and all work lost. (That’s the python module used for persistence of the model weights) Then the young grasshoppers learn about checkpointing and using our dev ops systems to make sure the environment is up to spec, but I feel this has to happen at least once to each Deep Learning researcher
- shashwat986 9y ago
  Something very similar happened to me. To this day, I don't run any python script without the `-i` flag

JimDabell 9y ago

One amusing one springs to mind: an image thumbnailer on a website for a very popular all-girl band. It was "smart" and cropped images to the right aspect ratio based on entropy in the image. In practice, this manifested itself as a foot fetish – if a photo included feet, it would centre the thumbnail on the feet almost every time. The gallery index pages looked quite odd.

cphoover 9y ago
I built a similar tool early in my career, only it used facial detection with haar cascade classifiers. It was kinda poorly written in PHP but it worked!

protomyth 9y ago

Tester worked a later shift (noon to 8pm) and was running scenarios. Got a really odd error that made contracted pricing incorrect. Developer came in the next morning and ran the scenario just fine. Tester repeated the scenario at 6:30PM and got the same error. Both thought the other was nuts and this went on for a week. Found out it was an interaction issue when using the time (UDT) to get the current market date. Lesson: if anything goes wrong at night but not during the morning, look at all the date code.

rmetzler 9y ago
I also found a test breaking on Mondays. Never on any other day. It tested a sum for the current week but made the mistake of creating models for "yesterday" which is on another week if it's the first day of the week (depending on location, Monday in Europe, Sunday in the USA).
- martinpw 9y ago
  Had an office where, every Thursday, one developer's machine would reboot at the same time late in the evening. It didn't happen to anyone else. Eventually he decided to stay late one Thursday and watch it to see what happened. At the appointed time the cleaner came by, unplugged his machine from the power socket and plugged in the vacuum cleaner to clean the room, and when done, plugged the machine back in.
  - dvtv75 9y ago
    Some decades ago, friends of mine ran an ISP that resold bandwidth from another business. They used a leased line to the business, and every Friday evening at about 7.30 their connection dropped out. It turned out that the cleaners at the remote end would plug their vacuum cleaner into the same circuit that was powering my friends' hardware. The power surge caused their hardware to crash, and nobody had access to properly reboot it until Monday 8.30am.
  - staikken 9y ago
    Heard a similar story about a laboratory system with tight environmental controls. Every so often the humidity would spike and the room would go out of tolerance after typical work hours. The designers of the system were under quite a bit of pressure until someone finally stuck around long enough to catch the janitor mopping the floors.

rlarkins 9y ago

Reset line for an embedded device coupling onto another line, error caused by noise on line was detected and handled in the debounce time for the reset line. Caused reset reason to report as an error even during normal resets.

noir_lord 9y ago

When I was young I wrote a system that had an error message that was "I'm sorry Dave, I'm afraid I can't do that" for a small local business (back in the 90's). 6mths after it was in production I got an email saying "The system won't work and it keeps calling me Dave!, I'm not called Dave, my name is Chris!". Lesson learnt right there, never put funny error messages in with the intention of replacing them later and never swear in error messages.

turc1656 9y ago

"ERROR: Task completed successfully"

deeteecee 9y ago
you got my vote for funniest here so far :)
grkvlt 9y ago
This is actually really common. I can't remember if it's Linux or Windows specific, but it is almost always caused by code like this: result = some_system_call(argv); if (result == ERROR) { do_something_else(); error_message = get_text_for_last_error(); display("ERROR: " + error_message); } What happens is that the call to `do_something_else()` calls another system call, which completes successfully. Unfortunately, system calls just return a success or failure code, and store the actual detailed error number in a shared global variable. So, when the handler code goes to retrieve the text message describing the error, it ends up looking up the code for the status of the second system call. But when that returned it saved the code for 'Task completed successfully' over the first error code the developer actually wanted... I think it's probably Windows, maybe the `perror()` call, that does this?

kolbe 9y ago

A finance quant created a strategy with amazing results. He discovered the theory, tested it, refined it, and set up a presentation to the portfolio manager to start running it. problem was that he inverted PnL, and had spent the previous couple weeks figuring out how to maximize losses. INBF "do the opposite." Markets don't work that way.

jerf 9y ago
What Silicon Valley startup did he land in after he was fired?

pwason 9y ago

Not really a bug, but.. An early release of our product (not to be named), contained a database that contained a perl script that was written out to a web server. The person who took over maintaining this script looked at the original author's code and put a comment line in containing the descriptive phrase "Chicken Goat Fuck Logic" (aka "CGF Logic"). We accidentally forgot to remove that comment before producing the "gold" CD. A couple of weeks later, a very large national youth organization (also not to be named) contacted us, saying they would be unable to use our software, because their CyberNanny software had detected swear words in the output. Arguably, if this hadn't happened, we would have become Amazon before Amazon became Amazon. Ooops!

metalliqaz 9y ago
why not named?
amatecha 9y ago
Rather humorously, it appears the person who wrote the script created this website to commemorate the birth of CGF Logic : http://chickengoatfuck.com/ http://chickengoatfuck.com/

billconan 9y ago

I had this bug that can reproduce only on a specific hp notebook, after running certain stress test for days. The issue (a crash) was in a device driver we were developing, but the root cause was because 1 single bit in the host memory was flipped randomly. My coworker joked that this bug was due to strong sunspot activities during those days (We indeed saw news about strong sunspot activities at the time.), so that strong universal radiation altered the data on the memory. I guess that batch of memory the notebook used had some issues. My background is purely software, I always thought that computer hardware is rigid and trustworthy. But I learnt from this bug that it's not always the case.

jeanmichelx 9y ago
That's what we want you to think, but the hardware is at least as much of a mess as the software
- Toast_25 9y ago
  Any sufficiently advanced technology is indistinguishable from chaos. Oh, wait, those were regexes.
aidos 9y ago
I had a similar one (almost 20 years ago!) where I came back from lunch to a panic about all the sites being down. The errors on all the sites were reporting a broken sql query - something like "select * from qccounts...". I guess the way ASP worked meant that the code was stored in a common location in memory for all the sites. I like to imagine some cosmic event millions of years ago flipped that bit...

AnimalMuppet 9y ago

An embedded system written in C++ had a Singleton. The Singleton pattern means that you have one instance, which has to live somewhere. This implementation had the instance as a static variable in the getInstance() method, e.g.: Foo* getInstance() { static Foo; return foo; } This is perfectly valid. Unfortunately, getInstance() was implemented in Foo.h, not in Foo.cpp. But in C++, functions in header files are inline by default. This means that every caller of Foo::getInstance() wound up with their own "static Foo" in their own inlined Foo::getInstance(), which meant that each caller got a different instance of the Singleton. Most interesting bug I've seen in ten years.

tgb 9y ago
Love the bug and it's been a while since I've done anything in C++, but isn't your description slightly wrong? There would be one instance per .cpp file that #include'd Foo.h, not one per getInstance() call. I don't think that "inline by default" is an accurate description of what would happen, and I have to imagine that if inline-ing a function caused different behavior, then that would be considered a compiler bug. Rather, I assume you mean it was "inlined" into the file at the #include point (and not once per call). Not that any of that changes the bug qualitatively.
- AnimalMuppet 9y ago
  No, inlining replaces it at the place of call. Every call, even if there's multiple of them in the same file. The idea is that, by putting the implementation in the .h file, you're signaling that you don't want to pay the overhead of the function call. (Same thing with the "inline" keyword.) Now, if your function is sufficiently complicated, the compiler may choose to not inline it anyway (with the definition of "sufficient" being compiler-dependent). It could be considered a compiler bug that a function with a static variable in the body could be inlined. As you say, that changes the behavior of the function. Or perhaps it could be considered a specification error - I don't know if the standard prohibits inlining in this circumstance, but perhaps it should.
  - 9y ago

jawns 9y ago

Ten years from now, A⍰ may look back on A⍰t and laugh, but for rA⍰ght now, there A⍰s nothA⍰ng funny about A⍰t!

mooseburger 9y ago

One I wrote myself. Frustrated with some bizarre bug that I struggled to reproduce, I added two popups, to two separate conditionals that should have been exclusive (either one or the other executes, but never both). The first one said "What", and the second one "the fuck". I eventually managed to get both to show up, correctly forming the expletive, but it wasn't enough to help me solve the bug. There were more bugs though, had to get the ticket list down, so I dropped it and went after some lower-hanging fruit. A week later, our dev team gets sent a chain email with two screenshots, and a brief comment from the lead saying "This should never happen." In the first screenshot, was my "What" popup. I didn't need to see the second one. Turns out, when I moved on to other tickets, I completely forgot I had left that code just lying there, instead of discarding it, and had even pushed it with nary a thought. Nobody else on the dev team had seen either popup. No one in QA saw them either. And so, it made it all the way to production, where one of our users (mercifully, an in-house one), promptly caught it. The dept head thought I was committing sabotage, given the very specific set of actions one had to take to see the effect, but thankfully everyone knew that it was too stupid to do something like that via commit into repo! At the least, my frustration at the bug proved justified.

JeanMarcS 9y ago
A classic one ! Once I did the same one, just an echo in a php page. It was at the bottom of the page, after the footer. It was a job for a web designer I was helping. It's his son who saw it. So we removed it before the client (or anyone, it was in production) feedback to us. Bullet dodged !

spatley 9y ago

Keyboard not found Press F1 to continue

AstralStorm 9y ago
This one actually makes sense. You can connect a keyboard later or send the key code over remote interface or serial port.

swanson 9y ago

As an undergrad doing an internship helping some PhD students write a complex MATLAB simulation. Part of the simulation needed to be done in a loop and, naturally, I used "i" as the index variable. I spent several days debugging why the expected output result was not correct. Turns out there were some calculations using complex numbers (e.g. `x = 2 + 3*i`) and MATLAB decided that I obviously wanted to redefine the imaginary number constant in the loop. It was not very funny at the time.

troymc 9y ago

For some reason, in some astrodynamics calculations, I multiplied by r^2 rather than dividing, and since r was on the order of 10^8, the answer was off by 32 orders of magnitude. (Yes, I now know about changing the units so that the numbers aren't so big; this was before I understood all that.)

psyc 9y ago

Today I noticed that the longer my game ran, the faster all the animations ran. At first I thought I was imagining it. I had accidentally find/replaced the delta time since last frame with time since app start.

rdtsc 9y ago

> What is the funniest bug you encountered? Spiders. Customer put one of our server in a shack outside the main building. Spiders and other bugs got in the server causing the hardware to fail. We never never thought of testing our against an arachnid infestation.

FigBug 9y ago

It wasn't funny at the time. I helped develop and app + hardware for measuring the force generated when luge / ski cross / boarder cross athletes start. The handles measure the force and sent the data to an iPad which also recorded video. Worked fine in the office. Every time we went up on the mountain to test, the video didn't work. Go back to the hotel it worked fine. Whole project was going to fail because of this. Finally it worked once on the mountain, so we proved the system could work. Finally I found the bug. When setting the video orientation, I was passing in device orientation instead of UI orientation. In my office, I always have my iPad on a stand, so device orientation matched ui orientation and everything worked fine. When I was on the mountain, I held the iPad flat so I could shield it from the sun with my body, then I'd lift it up when the athlete was about to start. The video would fail to record if device orientation was 'down' since that isn't a valid orientation to rotate video. I only ended up finding it because I ended up leaving my iPad stand at home one day.

jpatokal 9y ago

A bug that occurred only on Wednesdays: https://gyrovague.com/2015/07/29/crashes-only-on-wednesdays/ https://gyrovague.com/2015/07/29/crashes-only-on-wednesdays/

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petedoyle 9y ago

I was in Rome a while back and wanted to go see Michelangelo's David. Searched for "David of Michelangelo" in Google Maps for Android. Clicked details. The main detail photo's aspect ratio is very tall and--because the photo is center-cropped--results in a zoomed in look right below his waist. :) Gave me a laugh. It's still live...

arthurjj 9y ago

tl;dr If you have an Enum don't have the 0 value be semantically meaningful. 2nd tl;dr If sex/gender is an Enum you should have at least 4 values unspecified, female, male, other. A few years ago I was working on a front end that talked to different scheduling software systems. Our front end had a much more nuanced way of representing sex/gender while the system that talked to scheduling systems had an older enum Bad_Gender { female = 0, male = 1, } A bug was introduced such that no gender was set. However the field not being set meant that it's value was 0. This led to all appointments being booked as women. Even a prostate exam. Needless to say we fixed the bug quickly.

petemc_ 9y ago

This isn't exactly side-splitting, but my home isp, virgin media uk, does dns hijacking for domains they cannot resolve. If you try to access http://bugzilla.anynonworkingdomain.com http://bugzilla.anynonworkingdomain.com for some reason it interprets that as a search for the term "porn". I have lots of tabs open to our bugzilla in work (where bugzilla.mycompany.com resolves correctly) so when I take laptop home, open it up and chrome refreshes tabs it looks like I have opened 20 tabs searching for porn. https://imgur.com/a/fyu0D https://imgur.com/a/fyu0D

milesokeefe 9y ago
Interesting, seems to only trigger when the search term contains the substring 'bugzilla' exactly: http://advancedsearch2.virginmedia.com/main?FailedURI=bugzilla http://advancedsearch2.virginmedia.com/main?FailedURI=bugzil...

lj3 9y ago

I once worked on a retail time management game. The doors of your store would open and then close when the customers came in. After a while, the doors would just start swinging open and closed all the time, like the store was being visited by a vengeful ghost. We never did figure out what caused that. This next bug (in the same game) we purposefully left in and it became an easter egg. A big part of the game was being able to customize your store with different retail stands and tables to put your merchandise on. If you edited your store layout while customers were in the store, you could trap them. The path finding code we wrote for the customers required a valid point of entry and a valid point of exit to the store. As soon as you trapped the customer, the lack of valid path to an exit had an unusual effect on the character animation. The character movement and animation speed would increase up to 2x, which made the customer look like it was freaking out. It also negatively effected the customer "happiness" state. A store's reputation score was based on the average customer happiness level over a particular time period. A trapped customer could absolutely destroy that score. I've seen it drop from 2000+ to 0 in seconds. As with the other bug, we never did figure out why this was happening.

giomasce 9y ago

Did not happen to me, but it's really baffling! https://www.ibiblio.org/harris/500milemail.html https://www.ibiblio.org/harris/500milemail.html

bradknowles 9y ago
I know Trey Harris. I remember when he first posted about this. I was the Sr. Internet Mail Administrator for AOL at the time, and I just about passed out from laughing so hard.

locopati 9y ago

While testing Adobe Pagemaker 5.5 for the Power Mac (a version built specifically to take advantage of the new Apple hardware), I discovered a specific set of steps that would overwrite video memory and turn the screen into the kind of static fuzz you'd see in a television tuned to no channel (back when that was possible).

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dragonwriter 9y ago

I once worked tech support in a Fortune 500 enterprise software company where I got a support call that traced back to a syntax error causing a crash in the Perl install script of our flagship product. Only “funny” because it's a phenomenally expensive product with on paper substantial QA/QC, and yet somehow it got into release with an install script that was guaranteed to fail.

vinchuco 9y ago

Accidental vertical farming on an old version of farmville caused by a race condition due to slow satellite internet speeds. You could take valid actions that would otherwise be mutually exclusive.

newtronic 9y ago

Back in the late 1980's, apple released a version of Unix called A/UX. In order to get excitement going about it, they sold Macintosh computers with A/UX preloaded to developers. The combo was cheaper than the equivalent Mac. So I bought two of them. I also bought the biggest displays for them; they weighted like 50 lbs. Probably 400 x 512; I don't remember. Anyway, I hooked both up to their displays and both booted to this message: When in Danger Or in Doubt Run in Circles Scream and Shout! Apple eventually admitted that A/UX didn't support those giant monitors. I installed Mac OS and it ran fine.

togusa2017 9y ago

Wrote a rate limiter in C. It broke when time got adjusted due to day light savings . Didn't take into account negative time delta. It was an ahuh moment when I realized the next day

GFischer 9y ago
Relevant XKCD: https://xkcd.com/1883/ https://xkcd.com/1883/ And yes, I do hate working with timezones - and so does everyone else I guess, Outlook still fails to correctly send appointment invites across timezones when DST is involved.
- bradknowles 9y ago
  UTC FTW!

synicalx 9y ago

Not strictly an error or bug, but rather the cause of one. Back in my ISP days, we sold IPTV packages, which we in turn received from the IPTV company via satellite. And because of this elaborate distribution method we would get THE BEST outage/disruption notices. For example; "Urdu News will be unavailable from approximately 1AM GMT to 8PM, due to HIGH ENERGY SOLAR ACTIVITY." How much better is that than telling your customers "Your news is unavailable because Barry doesn't understand BGP"?!

vinchuco 9y ago

A different kind of bug https://www.npr.org/sections/krulwich/2013/06/19/193493225/the-love-that-dared-not-speak-its-name-of-a-beetle-for-a-beer-bottle https://www.npr.org/sections/krulwich/2013/06/19/193493225/t...

_nalply 9y ago

In a chemical simulation with OpenGL animation of molecules crashing into each other we used the wrong sign for the vectors after colliding. Instead moving in the opposite direction the molecules started to glue to each other. They kept moving around in ever growing chunks with wild psychedelic shapes. We kept this bug as an easter egg.

aaomidi 9y ago

So we have a channel in Telegram that mirrors hackernews... and this just happened so I guess it's a nice meta bug? https://i.imgur.com/JtbCGkB.png https://i.imgur.com/JtbCGkB.png (Disclaimer this doesn't happen, like ever)