and especially well with an application designed using the ideas of Flux. Default language mode that should be used when a package doesn't offer any insight. An Array of glob patterns. To be clear, I don't really care how this is achieved - I am submitting a feature request indicating that some form of no-side-effect validation check is useful in developer workflows. This is usually only needed in some very specific circumstances. An array of patterns for files and directories that aren't allowed to change when running installs with the `--immutable` flag set. Typically only needed if you have subprojects that aren't yet part of your workspace tree. This can be overruled on a by-command basis by manually setting the --immediate flag. By default, we don't assign unique IDs in the telemetry we send, so we have no way to know which data originates from which project. If you use nvm or similar, you should ensure that your PATH lists nvms shims before the version of Node.js installed by Homebrew. Defines the authentication credentials to use by default when accessing your registries (equivalent to _auth in the v1). For now, this is what I've come up with (on GitLab CI): a "yarn" job that runs yarn install --immutable, and then caches the .yarn directory using a cache key of the yarn.lock file. Consult the Telemetry page for more details about it. You will need to set up the PATH environment variable in your terminal to have access to Yarns binaries globally. This key represent the scope that's covered by the settings defined in the nested object. yarn install --immutable ends with status 0 (success) Git status shows working directory still clean Last commit is 27c650d95b3731c5b94ad3621ec75783badbde10 OS: local: Linux Manjaro CI: Linux Ubuntu 18.04.5 LTS Node version: local: v14.10.0 CI: v14.10.1 Yarn version: 2.2.2-git.20200923.4db8dee4 to join this conversation on GitHub . yarn install --immutable will abort if yarn.lock was to be modified as a result of the install. All examples in the Documentation are presented in ES2015.