Bump up minimum yarn version

[skellock]

Spent an hour with someone on the community site debugging an issue where ignite new Thing would create the directory and not put anything in it.

Turns out with his setup [email protected] and [email protected], both installed via brew (and no permissions issues; nor react-native installed globally) didn't work.

We tried --npm which didn't work.

Logging with --debug didn't show anything (which surprises me! -- possibly a bug? certainly not working as intended).

The solution to his problem was brew update && brew upgrade yarn.

Let's add another check for that combo:

if (node === '7.7.1' && yarn === '0.21.3') {
  console.warn('Good news!  We are about to save you a lot of time!  You should upgrade yarn.')
}

[skellock]

Related yarnpkg/yarn#2871

[ruddell]

Just for reference, I happen to use those exact versions and haven't had any issues. I installed yarn with npm, node with nvm, and use Mac.

I can update yarn/node, it just seems like a weird check to me.

My ignite doctor output (Click to expand)

System
  platform           darwin                                                                          
  arch               x64                                                                             
  cpu                8 cores                    Intel(R) Core(TM) i7-4850HQ CPU @ 2.30GHz  
  directory          /private/tmp/ignite/Test                                                        

JavaScript
  node               7.7.1        /Users/ruddell/.nvm/versions/node/v7.7.1/bin/node  
  npm                4.1.2        /Users/ruddell/.nvm/versions/node/v7.7.1/bin/npm   
  yarn               0.21.3       /Users/ruddell/.nvm/versions/node/v7.7.1/bin/yarn  

React Native
  react-native-cli   2.0.1       
  app rn version     0.42.0      

Ignite
  ignite             2.0.0-beta.9   /Users/ruddell/.nvm/versions/node/v7.7.1/bin/ignite  

Android
  java               1.8.0_60     /usr/bin/java                           
  android home       -            /usr/local/Cellar/android-sdk/24.4.1_1  

iOS
  xcode              8.3.2   

[skellock]

Cheers @ruddell . I wonder if yarn-from-brew vs. yarn-from-npm makes a difference?

[ruddell]

Brew is the recommended way to install yarn on Mac, installing via npm is actually warned against.

I don't think it's that big of a factor because Brew used to install Yarn with npm lol (this changed a month ago Homebrew/homebrew-core#11881)

[jamonholmgren]

@skellock I'm not sure if this needs to be fixed before 2.0 release. Happy to tackle it later.

[jamonholmgren]

I haven't seen issues with Yarn in a long time. Closing this.