| <!-- | |
| Copyright (C) Daniel Stenberg, <[email protected]>, et al. | |
| SPDX-License-Identifier: curl | |
| --> | |
| # BUGS | |
| ## There are still bugs | |
| Curl and libcurl keep being developed. Adding features and changing code | |
| means that bugs sneak in, no matter how hard we try to keep them out. | |
| Of course there are lots of bugs left. Not to mention misfeatures. | |
| To help us make curl the stable and solid product we want it to be, we need | |
| bug reports and bug fixes. | |
| ## Where to report | |
| If you cannot fix a bug yourself and submit a fix for it, try to report an as | |
| detailed report as possible to a curl mailing list to allow one of us to have | |
| a go at a solution. You can optionally also submit your problem in [curl's | |
| bug tracking system](https://github.com/curl/curl/issues). | |
| Please read the rest of this document below first before doing that. | |
| If you feel you need to ask around first, find a suitable [mailing list]( | |
| https://curl.se/mail/) and post your questions there. | |
| ## Security bugs | |
| If you find a bug or problem in curl or libcurl that you think has a security | |
| impact, for example a bug that can put users in danger or make them | |
| vulnerable if the bug becomes public knowledge, then please report that bug | |
| using our security development process. | |
| Security related bugs or bugs that are suspected to have a security impact, | |
| should be reported on the [curl security tracker at | |
| HackerOne](https://hackerone.com/curl). | |
| This ensures that the report reaches the curl security team so that they | |
| first can deal with the report away from the public to minimize the harm and | |
| impact it has on existing users out there who might be using the vulnerable | |
| versions. | |
| The curl project's process for handling security related issues is | |
| [documented separately](https://curl.se/dev/secprocess.html). | |
| ## What to report | |
| When reporting a bug, you should include all information to help us | |
| understand what is wrong, what you expected to happen and how to repeat the | |
| bad behavior. You therefore need to tell us: | |
| - your operating system's name and version number | |
| - what version of curl you are using (`curl -V` is fine) | |
| - versions of the used libraries that libcurl is built to use | |
| - what URL you were working with (if possible), at least which protocol | |
| and anything and everything else you think matters. Tell us what you expected | |
| to happen, tell use what did happen, tell us how you could make it work | |
| another way. Dig around, try out, test. Then include all the tiny bits and | |
| pieces in your report. You benefit from this yourself, as it enables us to | |
| help you quicker and more accurately. | |
| Since curl deals with networks, it often helps us if you include a protocol | |
| debug dump with your bug report. The output you get by using the `-v` or | |
| `--trace` options. | |
| If curl crashed, causing a core dump (in Unix), there is hardly any use to | |
| send that huge file to anyone of us. Unless we have the same system setup as | |
| you, we cannot do much with it. Instead, we ask you to get a stack trace and | |
| send that (much smaller) output to us instead. | |
| The address and how to subscribe to the mailing lists are detailed in the | |
| `MANUAL.md` file. | |
| ## libcurl problems | |
| When you have written your own application with libcurl to perform transfers, | |
| it is even more important to be specific and detailed when reporting bugs. | |
| Tell us the libcurl version and your operating system. Tell us the name and | |
| version of all relevant sub-components like for example the SSL library | |
| you are using and what name resolving your libcurl uses. If you use SFTP or | |
| SCP, the libssh2 version is relevant etc. | |
| Showing us a real source code example repeating your problem is the best way | |
| to get our attention and it greatly increases our chances to understand your | |
| problem and to work on a fix (if we agree it truly is a problem). | |
| Lots of problems that appear to be libcurl problems are actually just abuses | |
| of the libcurl API or other malfunctions in your applications. It is advised | |
| that you run your problematic program using a memory debug tool like valgrind | |
| or similar before you post memory-related or "crashing" problems to us. | |
| ## Who fixes the problems | |
| If the problems or bugs you describe are considered to be bugs, we want to | |
| have the problems fixed. | |
| There are no developers in the curl project that are paid to work on bugs. | |
| All developers that take on reported bugs do this on a voluntary basis. We do | |
| it out of an ambition to keep curl and libcurl excellent products and out of | |
| pride. | |
| Please do not assume that you can just lump over something to us and it then | |
| magically gets fixed after some given time. Most often we need feedback and | |
| help to understand what you have experienced and how to repeat a problem. | |
| Then we may only be able to assist YOU to debug the problem and to track down | |
| the proper fix. | |
| We get reports from many people every month and each report can take a | |
| considerable amount of time to really go to the bottom with. | |
| ## How to get a stack trace | |
| First, you must make sure that you compile all sources with `-g` and that you | |
| do not 'strip' the final executable. Try to avoid optimizing the code as well, | |
| remove `-O`, `-O2` etc from the compiler options. | |
| Run the program until it cores. | |
| Run your debugger on the core file, like `<debugger> curl core`. `<debugger>` | |
| should be replaced with the name of your debugger, in most cases that is | |
| `gdb`, but `dbx` and others also occur. | |
| When the debugger has finished loading the core file and presents you a | |
| prompt, enter `where` (without quotes) and press return. | |
| The list that is presented is the stack trace. If everything worked, it is | |
| supposed to contain the chain of functions that were called when curl | |
| crashed. Include the stack trace with your detailed bug report, it helps a | |
| lot. | |
| ## Bugs in libcurl bindings | |
| There are of course bugs in libcurl bindings. You should then primarily | |
| approach the team that works on that particular binding and see what you can | |
| do to help them fix the problem. | |
| If you suspect that the problem exists in the underlying libcurl, then please | |
| convert your program over to plain C and follow the steps outlined above. | |
| ## Bugs in old versions | |
| The curl project typically releases new versions every other month, and we | |
| fix several hundred bugs per year. For a huge table of releases, number of | |
| bug fixes and more, see: https://curl.se/docs/releases.html | |
| The developers in the curl project do not have bandwidth or energy enough to | |
| maintain several branches or to spend much time on hunting down problems in | |
| old versions when chances are we already fixed them or at least that they have | |
| changed nature and appearance in later versions. | |
| When you experience a problem and want to report it, you really SHOULD | |
| include the version number of the curl you are using when you experience the | |
| issue. If that version number shows us that you are using an out-of-date curl, | |
| you should also try out a modern curl version to see if the problem persists | |
| or how/if it has changed in appearance. | |
| Even if you cannot immediately upgrade your application/system to run the | |
| latest curl version, you can most often at least run a test version or | |
| experimental build or similar, to get this confirmed or not. | |
| At times people insist that they cannot upgrade to a modern curl version, but | |
| instead, they "just want the bug fixed". That is fine, just do not count on us | |
| spending many cycles on trying to identify which single commit, if that is | |
| even possible, that at some point in the past fixed the problem you are now | |
| experiencing. | |
| Security wise, it is almost always a bad idea to lag behind the current curl | |
| versions by a lot. We keep discovering and reporting security problems | |
| over time see you can see in [this | |
| table](https://curl.se/docs/vulnerabilities.html) | |
| # Bug fixing procedure | |
| ## What happens on first filing | |
| When a new issue is posted in the issue tracker or on the mailing list, the | |
| team of developers first needs to see the report. Maybe they took the day off, | |
| maybe they are off in the woods hunting. Have patience. Allow at least a few | |
| days before expecting someone to have responded. | |
| In the issue tracker, you can expect that some labels are set on the issue to | |
| help categorize it. | |
| ## First response | |
| If your issue/bug report was not perfect at once (and few are), chances are | |
| that someone asks follow-up questions. Which version did you use? Which | |
| options did you use? How often does the problem occur? How can we reproduce | |
| this problem? Which protocols does it involve? Or perhaps much more specific | |
| and deep diving questions. It all depends on your specific issue. | |
| You should then respond to these follow-up questions and provide more info | |
| about the problem, so that we can help you figure it out. Or maybe you can | |
| help us figure it out. An active back-and-forth communication is important | |
| and the key for finding a cure and landing a fix. | |
| ## Not reproducible | |
| We may require further work from you who actually see or experience the | |
| problem if we cannot reproduce it and cannot understand it even after having | |
| gotten all the info we need and having studied the source code over again. | |
| ## Unresponsive | |
| If the problem have not been understood or reproduced, and there is nobody | |
| responding to follow-up questions or questions asking for clarifications or | |
| for discussing possible ways to move forward with the task, we take that as a | |
| strong suggestion that the bug is unimportant. | |
| Unimportant issues are closed as inactive sooner or later as they cannot be | |
| fixed. The inactivity period (waiting for responses) should not be shorter | |
| than two weeks but may extend months. | |
| ## Lack of time/interest | |
| Bugs that are filed and are understood can unfortunately end up in the | |
| "nobody cares enough about it to work on it" category. Such bugs are | |
| perfectly valid problems that *should* get fixed but apparently are not. We | |
| try to mark such bugs as `KNOWN_BUGS material` after a time of inactivity and | |
| if no activity is noticed after yet some time those bugs are added to the | |
| `KNOWN_BUGS` document and are closed in the issue tracker. | |
| ## `KNOWN_BUGS` | |
| This is a list of known bugs. Bugs we know exist and that have been pointed | |
| out but that have not yet been fixed. The reasons for why they have not been | |
| fixed can involve anything really, but the primary reason is that nobody has | |
| considered these problems to be important enough to spend the necessary time | |
| and effort to have them fixed. | |
| The `KNOWN_BUGS` items are always up for grabs and we love the ones who bring | |
| one of them back to life and offer solutions to them. | |
| The `KNOWN_BUGS` document has a sibling document known as `TODO`. | |
| ## `TODO` | |
| Issues that are filed or reported that are not really bugs but more missing | |
| features or ideas for future improvements and so on are marked as | |
| *enhancement* or *feature-request* and get added to the `TODO` document and | |
| the issues are closed. We do not keep TODO items open in the issue tracker. | |
| The `TODO` document is full of ideas and suggestions of what we can add or | |
| fix one day. You are always encouraged and free to grab one of those items and | |
| take up a discussion with the curl development team on how that could be | |
| implemented or provided in the project so that you can work on ticking it odd | |
| that document. | |
| If an issue is rather a bug and not a missing feature or functionality, it is | |
| listed in `KNOWN_BUGS` instead. | |
| ## Closing off stalled bugs | |
| The [issue and pull request trackers](https://github.com/curl/curl) only hold | |
| "active" entries open (using a non-precise definition of what active actually | |
| is, but they are at least not completely dead). Those that are abandoned or | |
| in other ways dormant are closed and sometimes added to `TODO` and | |
| `KNOWN_BUGS` instead. | |
| This way, we only have "active" issues open on GitHub. Irrelevant issues and | |
| pull requests do not distract developers or casual visitors. | |