Automated testing in XGBoost project

This document collects tips for using the Continuous Integration (CI) service of the XGBoost project.

Contents

GitHub Actions

The configuration files are located under the directory .github/workflows.

Most of the tests listed in the configuration files run automatically for every incoming pull requests and every update to branches. A few tests however require manual activation:

• R tests with noLD option: Run R tests using a custom-built R with compilation flag --disable-long-double. See this page for more details about noLD. This is a requirement for keeping XGBoost on CRAN (the R package index). To invoke this test suite for a particular pull request, simply add a review comment /gha run r-nold-test. (Ordinary comment won’t work. It needs to be a review comment.)

GitHub Actions is also used to build Python wheels targeting MacOS Intel and Apple Silicon. See .github/workflows/python_wheels.yml. The python_wheels pipeline sets up environment variables prefixed CIBW_* to indicate the target OS and processor. The pipeline then invokes the script build_python_wheels.sh, which in turns calls cibuildwheel to build the wheel. The cibuildwheel is a library that sets up a suitable Python environment for each OS and processor target. Since we don’t have Apple Silion machine in GitHub Actions, cross-compilation is needed; cibuildwheel takes care of the complex task of cross-compiling a Python wheel. (Note that cibuildwheel will call setup.py bdist_wheel. Since XGBoost has a native library component, setup.py contains a glue code to call CMake and a C++ compiler to build the native library on the fly.)