what's the purpose of “--cache-builds” in carthage?

Question

As titled, what's the purpose of "--cache-builds" in carthage command line? if missing this, what could happen and what's the benefit to have this?

Answer 1

From docs:

Caching builds

By default Carthage will rebuild a dependency regardless of whether it's the same resolved version as before. Passing the --cache-builds will cause carthage to avoid rebuilding a dependency if it can. See information on version files for details on how Carthage performs this caching.

Note: At this time --cache-builds is incompatible with --use-submodules. Using both will result in working copy and committed changes to your submodule dependency not being correctly rebuilt.