Speeding up autoconf with caching

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2024-04-04 05:30:03

In the recent Remembering Buildtool post, I described how setting up a cache of configuration checks was an important step in Buildtool’s installation process. The goal was to avoid pointless repetitive work on every build by performing such common checks once.

Episode 457 of BSD Now featured my post and Allan Jude wondered how much time would be saved in a bulk build of all FreeBSD packages if we could just do that same kind of caching with GNU Autoconf. And, you know what? It is indeed possible to do so. I had mentioned it en passing in my post but I guess I wasn’t clear enough, so let’s elaborate!

A blog on operating systems, programming languages, testing, build systems, my own software projects and even personal productivity. Specifics include FreeBSD, Linux, Rust, Bazel and EndBASIC.

The configure scripts generated by GNU Autoconf are slow, very slow, to the point where sometimes their execution time is longer than the time it takes to build the package they configure. This is especially true on multi-core systems where these scripts make builds drag along.