This blog post has some good points about not blowing up the cache size - https://levans.fr/rust_travis_cache.html - See also [reddit](https://www.reddit.com/r/rust/comments/9d7sax/beware_the_rust_cache_on_travis_or_why_you_should/?st=jlph7q4o&sh=607527a4)
This blog post has some good points about not blowing up the cache size