問題と解決策：

一、問題:

Installation Problem: bash: yarn: command not found

ソリューション:

npm install -g yarn

参照先:

Installation Problem: bash: yarn: command not found #601

Yarn does not work in Git Bash on Windows #5349

Git Bash Command on Windows, yarn command not found

二、問題:

Building for production...Browserslist: caniuse-lite is outdated. Please run next command `npm update caniuse-lite browserslist`

ソリューション:なし.
三、問題:

npm WARN … requires a peer of … but none is installed. 
You must install peer dependencies yourself.

ソリューション:

 、Deprecated Solution:

1. You can use npm-install-peers to find and install required peer dependencies.

$ npm install -g npm-install-peers

$ npm-install-peers

2. If you are getting this error after updating any package's version then remove node_modules directory and reinstall packages by npm install or npm cache clean and npm install.

 、Updated Solution:

Use following for each peer dependency to install that and remove the error

$ npm install --save-dev xxxxx

参照先:

Browserslist: caniuse-lite is outdated

caniuse-lite is outdated.

npm WARN … requires a peer of … but none is installed. You must install peer dependencies yourself