*--frozen*::
*--locked*::
    Either of these flags requires that the `Cargo.lock` file is
    up-to-date. If the lock file is missing, or it needs to be updated, Cargo will
    exit with an error. The `--frozen` flag also prevents Cargo from
    attempting to access the network to determine if it is out-of-date.
+
These may be used in environments where you want to assert that the
`Cargo.lock` file is up-to-date (such as a CI build) or want to avoid network
access.
