Yarn 2 breaks application

[abenerd]

Describe the bug
Yarn 2 was released recently and the project appears to be incompatible with it.
I think we should either fix the version to yarn 1 (now legacy) or upgrade to yarn 2

To Reproduce

• Clone dev.to repository
• Run yarn version with yarn 2 or
• Run yarn install with yarn 2

Expected behavior
Yarn to work

Desktop (please complete the following information):

• OS: macOS Catalina
• Browser:
• Version: 10.15.2

Additional context

>>> yarn install
...
➤ YN0001: │ Error: fsevents@patch:fsevents@npm%3A2.0.7#builtin<compat/fsevents>::version=2.0.7&hash=e8cd9e: Cannot apply hunk #1
    at c (/Users/me/.yarn/releases/yarn-berry.js:58:888149)
    at runMicrotasks (<anonymous>)
    at processTicksAndRejections (internal/process/task_queues.js:97:5)
    at async /Users/me/.yarn/releases/yarn-berry.js:58:890280
    at async o (/Users/me/.yarn/releases/yarn-berry.js:58:887432)
    at async Object.t.applyPatchFile (/Users/me/.yarn/releases/yarn-berry.js:58:890253)
    at async t.PatchFetcher.patchPackage (/Users/me/.yarn/releases/yarn-berry.js:58:887187)
    at async /Users/me/.yarn/releases/yarn-berry.js:58:886444
    at async /Users/me/.yarn/releases/yarn-berry.js:36:569449
    at async /Users/me/.yarn/releases/yarn-berry.js:36:569392
...
➤ YN0013: │ yargs-parser@npm:4.2.1 can't be found in the cache and will be fetched from the remote registry
➤ YN0013: │ yargs-parser@npm:5.0.0 can't be found in the cache and will be fetched from the remote registry
➤ YN0013: │ yargs-parser@npm:7.0.0 can't be found in the cache and will be fetched from the remote registry
➤ YN0013: │ yargs-parser@npm:9.0.2 can't be found in the cache and will be fetched from the remote registry
➤ YN0013: │ yargs@npm:11.1.0 can't be found in the cache and will be fetched from the remote registry
➤ YN0013: │ yargs@npm:12.0.5 can't be found in the cache and will be fetched from the remote registry
➤ YN0013: │ yargs@npm:3.10.0 can't be found in the cache and will be fetched from the remote registry
➤ YN0013: │ yargs@npm:6.6.0 can't be found in the cache and will be fetched from the remote registry
➤ YN0013: │ yargs@npm:7.1.0 can't be found in the cache and will be fetched from the remote registry
➤ YN0013: │ yargs@npm:8.0.2 can't be found in the cache and will be fetched from the remote registry
➤ YN0000: └ Completed in 53.64s
➤ YN0000: Failed with errors in 1.28m

>>> yarn version
Internal Error: dev.to@workspace:.: This package doesn't seem to be present in your lockfile; try to make an install to update your resolutions
    at t.RunInstallPleaseResolver.getCandidates (/Users/me/.yarn/releases/yarn-berry.js:36:863677)
    at t.MultiResolver.getCandidates (/Users/me/.yarn/releases/yarn-berry.js:24:41320)
    at /Users/me/.yarn/releases/yarn-berry.js:36:581640
    at /Users/me/.yarn/releases/yarn-berry.js:36:857805
    at new Promise (<anonymous>)
    at e.exports (/Users/me/.yarn/releases/yarn-berry.js:36:857787)
    at i (/Users/me/.yarn/releases/yarn-berry.js:24:91764)
    at /Users/me/.yarn/releases/yarn-berry.js:24:91837
    at /Users/me/.yarn/releases/yarn-berry.js:24:91880
    at new Promise (<anonymous>)

[rhymes]

Hi @abenettt, thanks for the info!

According to the installation guide npm install yarn still installs Yarn 1, so on that side we're okay:

➜  devto git:(master) npm install yarn -g 
/Users/rhymes/.nvm/versions/node/v12.14.1/bin/yarnpkg -> /Users/rhymes/.nvm/versions/node/v12.14.1/lib/node_modules/yarn/bin/yarn.js
/Users/rhymes/.nvm/versions/node/v12.14.1/bin/yarn -> /Users/rhymes/.nvm/versions/node/v12.14.1/lib/node_modules/yarn/bin/yarn.js
+ yarn@1.21.1
added 1 package in 1.964s 

We might want to go over the documentation and the various parts where we mention Yarn and specify Yarn 1.

As Yarn 2 is largely incompatible with Yarn 1 and it seems to be generating issues with various packages I don't think we should rush into the upgrade anyway.

Let's fix the version to Yarn 1 in the meantime and we can keep an eye on Yarn 2.

Also, I'm quite sure the Rails webpack plugin we use it's not compatible with Yarn 2 so we couldn't upgrade anyway.

Would you be interested in going over the various places we mention Yarn and make sure we're telling people to use Yarn 1?

grepping results for yarn around the code

➜  devto git:(master) rg yarn | rg -v "yarn.lock"
Dockerfile:ENV PATH=/root/.yarn/bin:$PATH
Dockerfile:        yarn
Dockerfile:RUN yarn install && yarn check --integrity
README.md:- [Yarn](https://yarnpkg.com/): please refer to their
README.md:  [installation guide](https://yarnpkg.com/en/docs/install).
docker-entrypoint.sh:echo "alias devto-setup='cd /usr/src/app/ && gem install bundler && bundle install --jobs 20 --retry 5 && yarn install && yarn check --integrity && bin/setup'" >> ~/.bashrc
docker-entrypoint.sh:	echo ">    devto-setup   : Does the gem/yarn dependency installation, along with database setup"
package.json:    "api-docs:serve": "yarn redoc-cli serve docs/api_v0.yml --options.pathInMiddlePanel --options.jsonSampleExpandLevel=all --options.menuToggle -t docs/api_template.hbs --watch"
bin/update:  system('bin/yarn')
bin/setup:  system('bin/yarn')
bin/yarn:    exec "yarnpkg", *ARGV
bin/yarn:    $stderr.puts "Download Yarn at https://yarnpkg.com/en/docs/install"
docs/readme.md:yarn global add gitdocs
docs/contributing.md:yarn global add gitdocs
docs/contributing_api.md:yarn api-docs:serve
config/environments/production.rb:  config.webpacker.check_yarn_integrity = false
config/environments/development.rb:def yarn_integrity_enabled?
config/environments/development.rb:  config.webpacker.check_yarn_integrity = yarn_integrity_enabled?
docs/tests/preact-tests.md:yarn test
docs/tests/code-coverage.md:yarn test
docs/getting-started/committing.md:`yarn --force` or `npm install --no-cache`. For some reason, the post-install
docs/getting-started/committing.md:script of husky does not run when the package is pulled from yarn or npm's
docs/getting-started/start-app.md:`yarn install` before starting the app.
docs/installation/mac.md:Please refer to their [installation guide](https://yarnpkg.com/en/docs/install).
docs/installation/linux.md:  guide](https://yarnpkg.com/en/docs/install#debian-stable) (recommended).
docs/installation/linux.md:  run `npm install -g yarn` to install Yarn.
docs/installation/linux.md:issues while `yarn` is installing packages. If so, you'll need to [install
docs/installation/windows.md:curl -sS https://dl.yarnpkg.com/debian/pubkey.gpg | sudo apt-key add -
docs/installation/windows.md:echo "deb https://dl.yarnpkg.com/debian/ stable main" | sudo tee /etc/apt/sources.list.d/yarn.list
docs/installation/windows.md:sudo apt-get update && sudo apt-get install yarn
docs/installation/windows.md:Make sure that Yarn is installed with `yarn -v`
docs/installation/docker.md:1. run `docker-compose run web yarn install`
  

[abenerd]

I can do that, sure.

[maestromac]

Technically Resolved with #5786