v1.12.1

- Ensures the engine check is ran before showing the UI for `upgrade-interactive`

  [#6536](https://github.com/yarnpkg/yarn/pull/6536) - [**Orta Therox**](https://github.com/orta)

- Restores Node v4 support by downgrading `cli-table3`

  [#6535](https://github.com/yarnpkg/yarn/pull/6535) - [**Mark Stacey**](https://github.com/Gudahtt)

- Prevents infinite loop when parsing corrupted lockfiles with unterminated strings

  [#4965](https://github.com/yarnpkg/yarn/pull/4965) - [**Ryan Hendrickson**](https://github.com/rhendric)

- Environment variables now have to **start** with `YARN_` (instead of just contain it) to be considered

  [#6518](https://github.com/yarnpkg/yarn/pull/6518) - [**Michael Gmelin**](https://blog.grem.de)

- Fixes the `extensions` option when used by `resolveRequest`

  [#6479](https://github.com/yarnpkg/yarn/pull/6479) - [**Maël Nison**](https://twitter.com/arcanis)

- Fixes handling of empty string entries for `bin` in package.json

  [#6515](https://github.com/yarnpkg/yarn/pull/6515) - [**Ryan Burrows**](https://github.com/rhburrows)

- Adds support for basic auth for registries with paths, such as artifactory

  [#5322](https://github.com/yarnpkg/yarn/pull/5322) - [**Karolis Narkevicius**](https://twitter.com/KidkArolis)

- Adds 2FA (Two Factor Authentication) support to publish & alike

  [#6555](https://github.com/yarnpkg/yarn/pull/6555) - [**Krzysztof Zbudniewek**](https://github.com/neonowy)

- Fixes how the `files` property is interpreted to bring it in line with npm

  [#6562](https://github.com/yarnpkg/yarn/pull/6562) - [**Bertrand Marron**](https://github.com/tusbar)

- Fixes Yarn invocations on Darwin when the `yarn` binary was symlinked

  [#6568](https://github.com/yarnpkg/yarn/pull/6568) - [**Hidde Boomsma**](https://github.com/hboomsma)

- Fixes `require.resolve` when used together with the `paths` option

  [#6565](https://github.com/yarnpkg/yarn/pull/6565) - [**Maël Nison**](https://twitter.com/arcanis)