Migration to Yarn 4
Backstage projects created with @backstage/create-app
now use Yarn 4, you may have a previous version of Backstage that is still using Yarn 1 that you'll want to migrate, this tutorial will help you with this task.
Migration
In addition to this guide, also be sure to check out the Yarn migration guide as well.
Ignore File Updates
First off, be sure to have the updated ignore entries in your app. These are included in all newly created projects, but might be missing in yours:
Add the following to .gitignore
:
# Yarn files
.pnp.*
.yarn/*
!.yarn/patches
!.yarn/plugins
!.yarn/releases
!.yarn/sdks
!.yarn/versions
And this to .dockerignore
:
.yarn/cache
.yarn/install-state.gz