The sha256 value is usually calculated by the command:
$ shasum --algorithm 256 <file>The special value sha256 :no_check is used to turn off SHA checking whenever checksumming is impractical due to the upstream configuration.
version :latest requires sha256 :no_check, and this pairing is common. However, sha256 :no_check does not require version :latest.
We use a checksum whenever possible.