Yarn + Create React App Umbrella

[gaearon]

We shipped Yarn integration but there are a few small annoyances.
I'd like to consolidate them.

When they are fixed I'll feel comfortable recommending Yarn to CRA users more broadly.

• It looks like yarn@0.18 was released with latest tag for some time since it started failing our CI (Fix end-to-end test on Yarn #1167). I'm happy to help test Yarn by opting into using next builds on CI, but I want to make sure we have a process in place that Yarn RC releases don't become latest until they're well tested.
• In 0.18 (unstable), missing deps v0.18.0 postinstall missing dependencies yarnpkg/yarn#2142
• Not working with Heroku buildpack Building app does not work with yarn mars/create-react-app-buildpack#23
• Huge size on disk [feature] hint hoister algorithm yarnpkg/yarn#2306 https://twitter.com/nicdex/status/818606636919095296
• peerDependencies warning has a false positive Unmet peer dependency warning when the peer dependency is installed at the same time yarnpkg/yarn#2132
• Offline installation doesn't work Provide a way to fallback to cached version when installing latest offline yarnpkg/yarn#2225
• Yarn might not be installing binary dependencies (such as fsevents) Error in jest watch when using yarn for dependency installation #1474, Question: react-scripts start constantly @ 30% CPU #1670
• Global binaries reportedly don't get linked yarn global add doesn't install binaries properly yarnpkg/yarn#648, reported in Added option to disable yarn on initial build to fix jest failure #1370
• Local binaries get deleted react-scripts binary is disappeared #1439
• yarn global add doesn't work on Windows When installing global modules, Yarn tries to create .cmd file in wrong directory yarnpkg/yarn#2192
• yarn global add doesn't work with nvm "yarn global add" doesn't globally install packages if .yarn-cache was restored yarnpkg/yarn#1151 (comment)
• issues with flaky connections Doesn't work well on a flaky connection yarnpkg/yarn#746, Cannot install packages from github when offline yarnpkg/yarn#1925

[Daniel15]

I want to make sure we have a process in place that Yarn RC releases don't become latest until they're well tested.

This is tracked in yarnpkg/yarn#2161.

[ffxsam]

This issue I posted might be related:
yarnpkg/yarn#2229

I was excited to start using it with my Meteor projects, but went back to npm as I don't find yarn to be all that reliable.

[gaearon]

Also interesting: apparently installed size is larger with Yarn? https://twitter.com/petrhurtak/status/812356423795568640

[gaearon]

Apparently the disk size issue is very bad.
https://twitter.com/nicdex/status/818606636919095296

[Daniel15]

The disk size issue might be related to yarnpkg/yarn#2306. It'd be worth opening an issue on the Yarn GitHub project to track it.

[gaearon]

Another issue report related to binaries: #1370.
Not sure if diagnosis is correct.