Rust and Travis CI cache
Using Travis CI's cache is very useful and helps cut Rust job times way, way down. However, the way that the default caching for Cargo is set up means it will quickly bloat.
Travis currently checks
target/ for any changes from the current cache after a
build. There will always be changes in
target/ if the source has changed, which it usually does
when a Travis build runs. This means new incremental object files, fingerprints, and build script
compilation files are being added to the cache every build.