// -*- mode:doc; -*- // vim: set syntax=asciidoc: Contributing to Buildroot ========================= There are many ways in which you can contribute to Buildroot: analyzing and fixing bugs, analyzing and fixing package build failures detected by the autobuilders, testing and reviewing patches sent by other developers, working on the items in our TODO list and sending your own improvements to Buildroot or its manual. The following sections give a little more detail on each of these items. If you are interested in contributing to Buildroot, the first thing you should do is to subscribe to the Buildroot mailing list. This list is the main way of interacting with other Buildroot developers and to send contributions to. If you aren't subscribed yet, then refer to xref:mailing-list-subscribe[]. If you are going to touch the code, it is highly recommended to use a git repository of Buildroot, rather than starting from an extracted source code tarball. Git is the easiest way to develop from and directly send your patches to the mailing list. Refer to xref:getting-buildroot[] for more information on obtaining a Buildroot git tree. Reproducing, analyzing and fixing bugs -------------------------------------- A first way of contributing is to have a look at the open bug reports in the https://bugs.busybox.net/buglist.cgi?product=buildroot[Buildroot bug tracker]. As we strive to keep the bug count as small as possible, all help in reproducing, analyzing and fixing reported bugs is more than welcome. Don't hesitate to add a comment to bug reports reporting your findings, even if you don't yet see the full picture. Analyzing and fixing autobuild failures --------------------------------------- The Buildroot autobuilders are a set of build machines that continuously run Buildroot builds based on random configurations. This is done for all architectures supported by Buildroot, with various toolchains, and with a random selection of packages. With the large commit activity on Buildroot, these autobuilders are a great help in detecting problems very early after commit. All build results are available at http://autobuild.buildroot.org[], statistics are at http://autobuild.buildroot.org/stats.php[]. Every day, an overview of all failed packages is sent to the mailing list. Detecting problems is great, but obviously these problems have to be fixed as well. Your contribution is very welcome here! There are basically two things that can be done: - Analyzing the problems. The daily summary mails do not contain details about the actual failures: in order to see what's going on you have to open the build log and check the last output. Having someone doing this for all packages in the mail is very useful for other developers, as they can make a quick initial analysis based on this output alone. - Fixing a problem. When fixing autobuild failures, you should follow these steps: . Check if you can reproduce the problem by building with the same configuration. You can do this manually, or use the http://git.buildroot.org/buildroot-test/tree/utils/br-reproduce-build[br-reproduce-build] script that will automatically clone a Buildroot git repository, checkout the correct revision, download and set the right configuration, and start the build. . Analyze the problem and create a fix. . Verify that the problem is really fixed by starting from a clean Buildroot tree and only applying your fix. . Send the fix to the Buildroot mailing list (see xref:submitting-patches[]). In case you created a patch against the package sources, you should also send the patch upstream so that the problem will be fixed in a later release, and the patch in Buildroot can be removed. In the commit message of a patch fixing an autobuild failure, add a reference to the build result directory, as follows: --------------------- Fixes http://autobuild.buildroot.org/results/51000a9d4656afe9e0ea6f07b9f8ed374c2e4069 --------------------- [[submitting-patches]] Submitting patches ------------------ [NOTE] _Please, do not attach patches to bugs, send them to the mailing list instead_. When your changes are done, and committed in your local git view, _rebase_ your development branch on top of the upstream tree before generating the patch set. To do so, run: --------------------- $ git fetch --all --tags $ git rebase origin/master --------------------- Here, you are ready to generate then submit your patch set. To generate it, run: --------------------- $ git format-patch -M -n -s -o outgoing origin/master --------------------- This will generate patch files in the +outgoing+ subdirectory, automatically adding the +Signed-off-by+ line. Once patch files are generated, you can review/edit the commit message before submitting them using your favorite text editor. Lastly, send/submit your patch set to the Buildroot mailing list: --------------------- $ git send-email --to buildroot@buildroot.org outgoing/* --------------------- Note that +git+ should be configured to use your mail account. To configure +git+, see +man git-send-email+ or google it. Make sure posted *patches are not line-wrapped*, otherwise they cannot easily be applied. In such a case, fix your e-mail client, or better, use +git send-email+ to send your patches. Cover letter ~~~~~~~~~~~~ If you want to present the whole patch set in a separate mail, add +--cover-letter+ to the +git format-patch+ command (see +man git-format-patch+ for further information). This will generate a template for an introduction e-mail to your patch series. A 'cover letter' may be useful to introduce the changes you propose in the following cases: * large number of commits in the series; * deep impact of the changes in the rest of the project; * RFC footnote:[RFC: (Request for comments) change proposal]; * whenever you feel it will help presenting your work, your choices, the review process, etc. Patch revision changelog ~~~~~~~~~~~~~~~~~~~~~~~~ When improvements are requested, the new revision of each commit should include a changelog of the modifications between each submission. Note that when your patch series is introduced by a cover letter, the changelog may be added in the cover letter rather than in the individual commits. When added to the individual commits, this changelog is added when editing the commit message. Below the +Signed-off-by+ section, add +---+ and your changelog. Although the changelog will be visible for the reviewers in the mail thread, as well as in http://patchwork.buildroot.org[patchwork], +git+ will automatically ignores lines below +---+ when the patch will be merged. This is the intended behavior: the changelog is not meant to be preserved forever in the +git+ history of the project. Hereafter the recommended layout: --------------- Patch title less than 80-character length Some more paragraph giving some more details. And yet another paragraph giving more details. Signed-off-by: John Doe --- Changes v2 -> v3: - foo bar (suggested by Jane) - bar buz Changes v1 -> v2: - alpha bravo (suggested by John) - charly delta --------------- Any patch revision should include the version number. The version number is simply composed of the letter +v+ followed by an +integer+ greater or equal to two (i.e. "PATCH v2", "PATCH v3" ...). This can be easily handled with +git format-patch+ by using the option +--subject-prefix+: --------------------- $ git format-patch --subject-prefix "PATCH v4" \ -M -o outgoing origin/master --------------------- Reviewing/Testing patches ------------------------- The review process for new patches is done over the mailing list. Once a patch is submitted to the mailing list, other developers will provide feedback to the patch via emails sent through the mailing list. In the review process, do not hesitate to respond to patch submissions for remarks, suggestions or anything that will help everyone to understand the patches and make them better. Please use internet style replies in plain text emails when responding to patch submissions. Some tags are used to help following the state of any patch posted on the mailing-list: Tested-by:: Indicates that the patch has been tested in one way or another. You are encouraged to specify what kind of testing you performed (compile-test on architecture X and Y, runtime test on target A, ...). This additional information helps other testers and the maintainer. Reviewed-by:: Indicates that you code-reviewed the patch and did your best in spotting problems, but you are not sufficiently familiar with the area touched to provide an Acked-by tag. This means that there may be remaining problems in the patch that would be spotted by someone with more experience in that area. Should such problems be detected, your Reviewed-by tag remains appropriate and you cannot be blamed. Acked-by:: Indicates that you code-reviewed the patch and you are familiar enough with the area touched to feel that the patch can be committed as-is (no additional changes required). In case it later turns out that something is wrong with the patch, your Acked-by could be considered inappropriate. The difference between Acked-by and Reviewed-by is thus mainly that you are prepared to take the blame on Acked patches, but not on Reviewed ones. If you reviewed a patch and have comments on it, you should simply reply to the patch stating these comments, without providing a Reviewed-by or Acked-by tag. These tags should only be provided if you judge the patch to be good as it is. It is important to note that neither Reviewed-by nor Acked-by imply that testing has been performed. To indicate that you both reviewed and tested the patch, provide two separate tags (Reviewed/Acked-by and Tested-by). Note also that _any developer_ can provide Tested/Reviewed/Acked-by tags, without exception, and we encourage everyone to do this. Buildroot does not have a defined group of _core_ developers, it just so happens that some developers are more active than others. The maintainer will value tags according to the track record of their submitter. Tags provided by a regular contributor will naturally be trusted more than tags provided by a newcomer. As you provide tags more regularly, your 'trustworthiness' (in the eyes of the maintainer) will go up, but _any_ tag provided is valuable. Buildroot's Patchwork website can be used to pull in patches for testing purposes. Please see xref:apply-patches-patchwork[] for more information on using Buildroot's Patchwork website to apply patches. [[reporting-bugs]] Reporting issues/bugs, get help ------------------------------- Before reporting any issue, please check xref:mailing-list-subscribe[the mailing list archive] in case someone has already reported and fixed a similar problem. However you choose to report bugs or get help, xref:bugtracker[opening a bug] or xref:mailing-list-subscribe[send a mail to the mailing list], there are a number of details to provide in order to help people reproduce and find a solution to the issue. Try to think as if you were trying to help someone else; in that case, what would you need? Here is a short list of details to provide in such case: * host machine (OS/release) * version of Buildroot * target for which the build fails * package(s) which the build fails * the command that fails and its output * any information you think that may be relevant Additionnally, your can add the +.config+ file. If some of these details are too large, do not hesitate to use a pastebin service (see http://www.similarsitesearch.com/alternatives-to/pastebin.com[]).