`yarn add` with package already installed removes the package

[remorses]

when using workspaces

Bug description

yarn add with package already installed removes the package It happens when using the latest tag Command

yarn add recharts@latest
yarn add recharts@latest

then i won't find recharts in node_modules

Steps to Reproduce

1. create some workspaces packages (not sure if happens without workspaces)
2. install 2 times a package
3. try import the package or check the root node_modules

Environment

• Node Version: 12.13
• Yarn v1 Version: 1.22.4
• OS and version: Mac Catalina

[lsliwaradioluz]

I believe it also happens without the @latest tag. Also, I've noticed it happens for dependencies with ^ or ~ standing before the version number in package.json. For packages with a fixed version number, the problem does not occur.