Yarn 3.0.0

Sponsorship Yarn now accepts sponsorships! Please give a look at our OpenCollective and GitHub Sponsors pages for more details. Master Note: features in master can be tried out by running yarn set version from sources in your project (existing contrib plugins are updated automatically, while new contrib plugins can be added by running yarn plugin…


Yarn now accepts sponsorships! Please give a look at our OpenCollective and GitHub Sponsors pages for more details.


Note: features in master can be tried out by running yarn set version from sources in your project (existing contrib plugins are updated automatically, while new contrib plugins can be added by running yarn plugin import from sources ).


Breaking Changes

  • Node 10 isn’t supported anymore.
  • Plugins can’t access yup anymore (we migrated to Typanion as part of Clipanion v3).
    • To upgrade workspace-tools, remove it from your .yarnrc.yml, upgrade, then import it back.
  • The enableImmutableInstalls will now default to true on CI (we still recommend to explicitly use --immutable on the CLI).
    • You can re-allow mutations by adding YARN_ENABLE_IMMUTABLE_INSTALLS=false in your environment variables.
  • The initVersion and initLicense configuration options have been removed. initFields should be used instead.
  • Yarn will now generate .pnp.cjs files (instead of .pnp.js) when using PnP, regardless of what the type field inside the manifest is set to.
  • The virtual folder (used to disambiguate peer dependencies) got renamed from $$virtual into __virtual__.
  • The -a alias flag of yarn workspaces foreach got removed; use -A,--all instead, which is strictly the same.
  • The old PnPify SDK folder (.vscode/pnpify) won’t be cleaned up anymore.
  • The --skip-builds flag from yarn install got renamed into --mode=skip-build.
  • The bstatePath configuration option has been removed. The build state (.yarn/build-state.yml) has been moved into the install state (.yarn/install-state.gz)
  • The cache files need to be regenerated. We had to change their timestamps in order to account for a flaw in the zip spec that was causing problems with some third-party tools.
  • @yarnpkg/pnpify has been refactored into 3 packages:
  • @yarnpkg/plugin-node-modules has been renamed to @yarnpkg/plugin-nm
  • The --clipanion=definitions commands supported by our CLIs will now expose the definitions on the entry point (rather than on .command)


  • structUtils.requirableIdent got removed; use structUtils.stringifyIdent instead, which is strictly the same.
  • configuration.format got removed; use formatUtils.pretty instead, which is strictly the same, but type-safe.
  • httpUtils.Options['json'] got removed; use httpUtils.Options['jsonResponse'] instead, which is strictly the same.
  • PackageExtension['description'] got removed, use formatUtils.json(packageExtension, formatUtils.Type.PACKAGE_EXTENSION) instead, which is strictly the same.
  • Project.generateBuildStateFile has been removed, the build state is now in Project.storedBuildState.
  • Project.tryWorkspaceByDescriptor and Project.getWorkspaceByDescriptor now match on virtual descriptors.


  • Workspaces now get self-references even when under the node-modules linker (just like how it already worked with the pnp linker). This means that a workspace called foo can now safely assume that calls to require('foo/package.json') will always work, removing the need for absolute aliases in the majority of cases.

  • The node-modules linker now does its best to support the portal: protocol. This support comes with two important limitations:

    • Projects that make use of such dependencies will have to be run with the --preserve-symlinks Node option if they wish to access their dependencies.
    • Because Yarn installs will never modify files outside of the project due to security reasons, sub-dependencies of packages with portal: must be hoisted outside of the portal. Failing that (for example if the portal package depends on something incompatible with the version hoisted via another package), the linker will produce an error and abandon the install.
  • The node-modules linker can now utilize hardlinks. The new setting nmMode: classic | hardlinks-local | hardlinks-global specifies which node_modules strategy should be used:

    • classic – standard node_modules layout, without hardlinks
    • hardlinks-local – standard node_modules layout with hardlinks inside the project only
    • hardlinks-global – standard node_modules layout with hardlinks pointing to global content storage across all the projects using this option


  • Yarn now has a proper governance model.
  • The node-modules linker will now ensure that the generated install layouts are terminal, by doing several rounds when needed.
  • The node-modules linker will no longer print warnings about postinstall scripts when a workspace depends on another workspace listing install scripts.
  • Peer dependencies depending on their own parent are now properly hoisted by the node-modules linker.
  • Boolean values will be properly interpreted when specified inside the configuration file via the ${ENV_VAR} syntax.
  • Should any of preinstall, install, postinstall fail, the remaining scripts will be skipped.
  • The git: protocol will now default to fetching HEAD (rather than the hardcoded master).
  • The SIGTERM signal will now be propagated to child processes.
  • The PnP linker now schedules packages to be rebuilt if their unplugged folder is removed
  • yarn config unset will now correctly unset non-nested properties
  • The TypeScript SDK now
  • And a bunch of smaller fixes.


  • Various initFields edge cases have been fixed.
  • The preferAggregateCacheInfo flag will now also aggregate cleanup reports.
  • A new enableMessageNames flag can be set to false to exclude the YNxxxx from the output.


  • yarn init can now be run even from within existing projects (will create missing files).
  • yarn init and yarn set version will set the packageManager field.
  • yarn set version now downloads binaries from the official Yarn website (rather than GitHub).
  • yarn set version from sources will now upgrade the builtin plugins as well unless --skip-plugins is set.
  • yarn version apply now supports a new --prerelease flag which replaces how prereleases were previously handled.
  • yarn run should be significantly faster to boot on large projects.
  • yarn workspaces foreach --verbose will now print when processes start and end, even if they don’t have an output.
  • yarn workspaces foreach now supports a --from flag, which when combined with -R will target workspaces reachable from the ‘from’ glob.
  • yarn patch-commit can now be used as many times as you want on the same patch folder.
  • yarn patch-commit now supports a new -s,--save flag which will save the patch instead of just printing it.
  • yarn up now supports a new -R,--recursive flag which will upgrade the specified package, regardless where it is.
  • yarn config unset is a new command that will remove a setting from the local configuration (or home if -H is set).
  • yarn exec got support for running shell scripts using Yarn’s portable shell.
  • yarn plugin import can now install specific versions of the official plugins.
  • yarn plugin import will now download plugins compatible with the current CLI by default.
  • yarn unlink has been added which removes resolutions previously set by yarn link.

Builtin Shell

  • The shell now supports background jobs, with color-coded output.
  • It now also supports redirections from file descriptors.


  • Running yarn install inside a Yarn v1 project will now automatically enable the node-modules linker. This should solve most of the problems people have had in their migrations. We still recommend to keep the default PnP for new projects, but the choice is yours.
  • The patched filesystem now supports file URLs, bigint, and fstat.
  • An official ESBuild resolver is now provided under the name @yarnpkg/esbuild-plugin-pnp. We use it to bundle Yarn itself!
  • PnP projects can now use the Node exports field – regardless of the Node version.
  • The PnP hook now supports the node: protocol (new in Node 16)
  • The Prettier SDK does not use PnPify anymore since it was its only remaining use, and was fairly invasive; as a result, the Prettier plugins must be specified in Prettier’s plugins configuration property.
  • Zip terminal links can now be clicked from within VSCode
  • Builtin patches that fail to apply will no longer cause an error (they’ll emit a warning and the original sources will be used instead).
    • Remember that patches are a problem for our team too, and that we only do this because we don’t have any other option available to us right now – if you wish to help, consider upvoting the relevant pull request in the TypeScript repository or, if you work at Microsoft, perhaps mention to your TypeScript team next door that fixing this would benefit you.


  • Reporting for HTTP errors has been improved, which should help you investigate registry issues.



  • The release of TypeScript 4.2 couldn’t be installed due to patch conflicts. This is now fixed. This version only includes a fix specific to 4.2, but future Yarn releases starting from 3.0 will be more tolerant of this kind of situation and won’t cause such errors.



  • The resolution pipeline got reimplemented. We previously used a multi-pass approach where we performed SAT optimization between each pass, but after investigating it turned out the SAT optims had little impact and added performance bottlenecks. We now run the resolution using a much simpler and more efficient algorithm.

  • Linkers can now define custom data to cache between Yarn invocations. The builtin linkers new use those new capabilities to cache package information that can’t change between runs. In practice, this translates into much faster recurrent installs (when running an install that adds few new packages, if any).

  • Warnings are now reported when packageExtensions rules are either unused or redundant with the original package definition.

  • Potentially breaking, but it was intended this way from the start: the packageExtensions field cannot be used to replace dependencies anymore (only to add missing ones). Prefer using the resolutions field to replace existing ones.

  • Progress bars are rendered less often, which should help performances on some terminals.

  • Aliased packages no longer include themselves in node_modules installs


  • The upgrade-interactive command will now only show upgrade suggestions for packages that have available upgrades (rather than all of them).

  • The upgrade-interactive command has received UI improvements that should make it easier to look at.

  • The yarn workspaces focus command will now only run the postinstall scripts for the focused workspaces.

  • A new yarn npm audit command lets you query audit information from the npm registry.

  • The yarn workspaces foreach command has a new flag, -R,--recursive, which will run a command on the current workspace and all others it depends on.

  • A new --skip-builds option on yarn install will let you skip the build scripts without impacting the generated Yarn artifacts (contrary to enableScripts, which would also stop unplugging the packages that would otherwise be unplugged due to containing build scripts).


  • It’s now possible to run dependency binaries when using the node-modules linker even if one of your other dependencies is reported as incompatible with your system.

  • By default Windows automatically requests for administrator rights before spawning any binary whose filename contains “install”, “setup”, “update”, or “patch” (it thinks they are installers). We now explicitly opt-out of this behavior in the binary jumpers we use on Windows.

  • By default, arguments passed to MinGW-compiled programs are automatically expanded by a basic glob pattern engine. We now explicitly opt-out of this behavior in the binary jumpers we use on Windows.

  • The Windows binary jumpers will now report the right exit code.


  • Using empty fallbacks in Yarnrc environment variables (${VAR:-}) will now work.

  • You can now use the new logFilters setting to turn warnings into either errors or info, or to hide them entirely. Note that we plan to significantly improve the peer dependency warnings in the next release, so perhaps don’t silence them just now even if you have a bunch of them.


  • Some shell errors (No matches found, Bad file descriptor, Unbound variable, Unbound argument) will now be recoverable errors that make the shell continue on to the next command in the chain instead of hard crashes. Fixes cases such as rm -rf ./inexistentFolder/|| true.

VSCode ZipFS Extension

  • The extension will now activate even if the workspace doesn’t contain zip files (usually because you excluded them).


  • Some patches went missing for TypeScript <4. This is now fixed.

  • Calling fs.exists(undefined) won’t crash an

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