Autoconf’s revenge: ad-hoc shell templates

How to leverage an old dirty trick in your Bazel wrapper for great effect As powerful as Bazel is, sometimes it’s not featureful enough. When using this build system, it’s common practice to wrap it in a launcher script—and in fact, this is natively supported by Bazelisk, Bazel’s native dispatcher that stands for the bazel binary in the user’s PATH. Bazelisk will first download the version of Bazel requested by the project, and then, if tools/bazel exists, invoke it instead of the downloaded binary. tools/bazel is what’s known as a Bazel wrapper and is the point of today’s article. Well, not quite. The actual point of today’s article is to demonstrate a simple trick I learned from the GNU Autoconf and Automake days to implement full-blown conditionals in an ad-hoc template system. But because such trick is trivial once you see it, I have to present it in the context of a modern real-world scenario. So what I’m going to do is guide you through the creation of your very own Bazel…