Uploading/downloading gigabytes of data on S3 is slow. It’d be nice to have a network local cache. Caching derived data locally would enable a large speedup for iOS builds. Even better would be to have transparent caching of all the network artifacts (git clone/carthage/ruby/etc.). Then when carthage flakes out, the build doesn’t fail.
I definitely agree, both with a network-local cache and with a “transparent” network cache.
Thanks for the feature request @bootstraponline!