Cees-Jan Kiewiet has posted an article covering the
cache directive on The popular Travis-CI continuous integration service and how it can have an effect on your builds.
Ever since the Test lowest, current, and highest possible on Travis post I wanted to dive into caching composers cache and vendor on Travis. My experiments started the day after that post.
He starts with an example of a simple
.travis.yml build configuration that includes the
cache directive, showing the caching of entire directories. He points out that, while this can speed up builds, it also comes with a few problems - one being that cache inconsistencies could cause unintended side effects when major changes are made. He points out that most of these risks are worth the gain, though. He's seen a gain of around 40 seconds for a normally 50 second job.