Continuous Integration for the Coq Proof Assistant ================================================== Changes to Coq are systematically tested for regression and compatibility breakage on our Continuous Integration (CI) platforms *before* integration, so as to ensure better robustness and catch problems as early as possible. These tests include the compilation of several external libraries / plugins. This document contains information for both external library / plugin authors, who might be interested in having their development tested, and for Coq developers / contributors, who must ensure that they don't break these external developments accidentally. *Remark:* the CI policy outlined in this document is susceptible to evolve and specific accommodations are of course possible. Information for external library / plugin authors ------------------------------------------------- You are encouraged to consider submitting your development for addition to our CI. This means that: - Any time that a proposed change is breaking your development, Coq developers will send you patches to adapt it or, at the very least, will work with you to see how to adapt it. On the condition that: - At the time of the submission, your development works with Coq master branch. - Your development is publicly available in a git repository and we can easily send patches to you (e.g. through pull / merge requests). - You react in a timely manner to discuss / integrate those patches. - You do not push, to the branches that we test, commits that haven't been first tested to compile with the corresponding branch(es) of Coq. - You maintain a reasonable build time for your development, or you provide a "lite" target that we can use. In case you forget to comply with these last three conditions, we would reach out to you and give you a 30-day grace period during which your development would be moved into our "allow failure" category. At the end of the grace period, in the absence of progress, the development would be removed from our CI. ### Add your development by submitting a pull request Add a new `ci-mydev.sh` script to [`dev/ci`](.); set the corresponding variables in [`ci-basic-overlay.sh`](ci-basic-overlay.sh); add the corresponding target to [`Makefile.ci`](../../Makefile.ci) and a new job to [`.gitlab-ci.yml`](../../.gitlab-ci.yml) so that this new target is run. Have a look at [#7656](https://github.com/coq/coq/pull/7656/files) for an example. **Do not hesitate to submit an incomplete pull request if you need help to finish it.** You may also be interested in having your development tested in our performance benchmark. Currently this is done by providing an OPAM package in https://github.com/coq/opam-coq-archive and opening an issue at https://github.com/coq/coq-bench/issues. Information for developers -------------------------- When you submit a pull request (PR) on Coq GitHub repository, this will automatically launch a battery of CI tests. The PR will not be integrated unless these tests pass. We are currently running tests on the following platforms: - GitLab CI is the main CI platform. It tests the compilation of Coq, of the documentation, and of CoqIDE on Linux with several versions of OCaml / camlp5, and with warnings as errors; it runs the test-suite and tests the compilation of several external developments. - Travis CI is used to test the compilation of Coq and run the test-suite on macOS. It also runs a linter that checks whitespace discipline. A [pre-commit hook](../tools/pre-commit) is automatically installed by `./configure`. It should allow complying with this discipline without pain. - AppVeyor is used to test the compilation of Coq and run the test-suite on Windows. You can anticipate the results of most of these tests prior to submitting your PR by running GitLab CI on your private branches. To do so follow these steps: 1. Log into GitLab CI (the easiest way is to sign in with your GitHub account). 2. Click on "New Project". 3. Choose "CI / CD for external repository" then click on "GitHub". 4. Find your fork of the Coq repository and click on "Connect". 5. If GitLab did not do so automatically, [enable the Container Registry](https://docs.gitlab.com/ee/user/project/container_registry.html#enable-the-container-registry-for-your-project). 6. You are encouraged to go to the CI / CD general settings and increase the timeout from 1h to 2h for better reliability. Now everytime you push (including force-push unless you changed the default GitLab setting) to your fork on GitHub, it will be synchronized on GitLab and CI will be run. You will receive an e-mail with a report of the failures if there are some. You can also run one CI target locally (using `make ci-somedev`). See also [`test-suite/README.md`](../../test-suite/README.md) for information about adding new tests to the test-suite. ### Breaking changes When your PR breaks an external project we test in our CI, you must prepare a patch (or ask someone to prepare a patch) to fix the project: 1. Fork the external project, create a new branch, push a commit adapting the project to your changes. 2. Test your pull request with your adapted version of the external project by adding an overlay file to your pull request (cf. [`dev/ci/user-overlays/README.md`](user-overlays/README.md)). 3. Fixes to external libraries (pure Coq projects) *must* be backward compatible (i.e. they should also work with the development version of Coq, and the latest stable version). This will allow you to open a PR on the external project repository to have your changes merged *before* your PR on Coq can be integrated. On the other hand, patches to plugins (projects linking to the Coq ML API) can very rarely be made backward compatible and plugins we test will generally have a dedicated branch per Coq version. You can still open a pull request but the merging will be requested by the developer who merges the PR on Coq. There are plans to improve this, cf. [#6724](https://github.com/coq/coq/issues/6724). Moreover your PR must absolutely update the [`CHANGES`](../../CHANGES) file. Advanced GitLab CI information ------------------------------ GitLab CI is set up to use the "build artifact" feature to avoid rebuilding Coq. In one job, Coq is built with `./configure -prefix _install_ci` and `make install` is run, then the `_install_ci` directory persists to and is used by the next jobs. Artifacts can also be downloaded from the GitLab repository. Currently, available artifacts are: - the Coq executables and stdlib, in three copies varying in architecture and OCaml version used to build Coq. - the Coq documentation, built only in the `build:base` job. When submitting a documentation PR, this can help reviewers checking the rendered result. As an exception to the above, jobs testing that compilation triggers no OCaml warnings build Coq in parallel with other tests. ### GitLab and Windows If your repository has access to runners tagged `windows`, setting the secret variable `WINDOWS` to `enabled` will add jobs building Windows versions of Coq (32bit and 64bit). The Windows jobs are enabled on Coq's repository, where pipelines for pull requests run. ### GitLab and Docker System and opam packages are installed in a Docker image. The image is automatically built and uploaded to your GitLab registry, and is loaded by subsequent jobs. **IMPORTANT**: When updating Coq's CI docker image, you must modify the `CACHEKEY` variable in [`.gitlab-ci.yml`](../../.gitlab-ci.yml) and [`Dockerfile`](docker/bionic_coq/Dockerfile) The Docker building job reuses the uploaded image if it is available, but if you wish to save more time you can skip the job by setting `SKIP_DOCKER` to `true`. This means you will need to change its value when the Docker image needs to be updated. You can do so for a single pipeline by starting it through the web interface.. See also [`docker/README.md`](docker/README.md).