yarn install command ignoring if yarn.lock file exist

[OmerHerera]

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

What is the current behavior?
yarn install ignore existing yarn.lock file and install all modules with newest version

If the current behavior is a bug, please provide the steps to reproduce.
Run yarn install in a project that has yarn.lock file
See yarn.lock file created again, overriding old (see attached picture)

What is the expected behavior?
yarn must take into consideration if yarn.lock exist

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

OsX El Capitan 10.11.6
node v6.10.0
yarn 0.23.2

I think is the same here

[OmerHerera]

I got into the conclusion that if the yarn.lock file was changed manually (without using the yarn cli).
It fails integrity check and generate a new one, I was updating the file because there is a bug with sub-modules here.

I'm right about it?
Thanks

[bestander]

Yarn would update yarn.lock if there were changes to package.json, for example.