Add subsequent single packages quicker by not linking with others?

[laggingreflex]

Do you want to request a feature or report a bug?

Feature

What is the current behavior?

Doesn't exist

What is the expected behavior?

There should be a command that lets you add a single package without re-installing/checking/linking all existing packages.

So for example I have a project with a good amount of packages already installed. Now I want to add a new package. When I do yarn add <package-name> it goes through all the hoops of installing/linking/checking all the other dependencies that are already installed. Linking takes the most time. I trust it's to check and re-link inter-dependencies or to maintain overall integrity. But it's weird that it takes just as much time to add a single package, no matter how small or with howsoever little or no dependencies of its own it has.

npm@2 actually performs better in this scenario (in some conditions) by not having to bother maintaining compatibility or to go through de-duplication effort with parent's dependencies.

Adding subsequent packages without having their installation time inhibited by other installed packages would be awesome.

If the current behavior is a bug, please provide the steps to reproduce.

1. In a big project install dependencies as usual
2. then yarn add jquery (at mine it takes ~60s!! it's a small package with no deps, yet it takes 60s re-linking all previously installed ~1000 modules)
3. install npm@2 somewhere and use it to install the same (installs in <10s)

Please mention your node.js, yarn and operating system version.

node v6.8.1
yarn v0.15.1

[laggingreflex]

#1496 would also solve this tbh. I just thought this was normal - i.e. (re-)linking takes time. But then I saw how quick it is on linux machine (in the the above example it only takes <5-10s). It's actually how it should be on Windows too.

edit: #2176 fixes this as well.