Dear LibreOffice developers and contributors, I recently opened Bug 168776<https://bugs.documentfoundation.org/show_bug.cgi?id=168776> (https://bugs.documentfoundation.org/show_bug.cgi?id=168776) to propose migrating the LibreOffice build system from Make, autotools, and Perl to Bazel. In the discussion there, I was advised to bring this topic to this mailing list for broader feedback and discussion.
I believe such a migration could bring several benefits and simplifications, including: * Incremental Builds: Bazel can significantly reduce compilation time compared to the current Make-based system. * Simplified File Structure: As of October 2025, LibreOffice contains about 2,581 Makefiles. This could be reduced to around 150 BUILD.bazel files (roughly one per module). * Unified Testing: bazel test would remove the need for separate Makefiles for unit tests. * Modern Build Language: Legacy Perl scripts could be replaced by the modern, Python-like Starlark language. * Refactoring Opportunity: The current integration among autotools, gbuild, and Perl scripts makes refactoring legacy OpenOffice-era code difficult. * Module Management: Bazel’s MODULE.bazel and http_archive features can consolidate external dependencies into a single configuration file, rather than the scattered external/ directory. * Cross-Platform Builds: select() expressions can cleanly handle platform-specific build options. I understand that such a migration would involve a significant transition period and changes to the CI infrastructure. However, as LibreOffice continues to grow in complexity and scale, modernizing the build system could improve maintainability, reproducibility, and the onboarding experience for new developers. In short, Bazel could modernize LibreOffice’s build process, reduce maintenance burden, and improve reproducibility. I’d like to ask whether there have been any previous attempts or internal discussions on this topic, and whether a partial or per-module migration could be considered as a starting point. Thank you for your time and consideration. Best regards, Haruhiko Nishizaki
