Peer dependency warning

[oliviertassinari]

When installing @material-ui/lab@v5.0.0-alpha.16 with date-fns, a developer gets the following warnings:

warning "@material-ui/lab > @date-io/dayjs@2.10.6" has unmet peer dependency "dayjs@^1.8.17".
warning "@material-ui/lab > @date-io/luxon@2.10.6" has unmet peer dependency "luxon@^1.21.3".
warning "@material-ui/lab > @date-io/moment@2.10.6" has unmet peer dependency "moment@^2.24.0".

Is there a way we could solve them? cc @eps1lon.

I'm using yarn v1.22.4.

[eps1lon]

We already solved this for the package managers that can solve them (yarn 2 and npm 6) with peerDependenciesMeta. We can close this if you can't reproduce them with yarn 2. For yarn 1 only we can close this issue.

Either way, it's not an issue for date-io but the packages depending on date-io. In this case: @material-ui/lab.

[oliviertassinari]

Regarding npm 7, there are no warnings when installing @material-ui/lab :). However, it installs all the peer dependencies. You have date-fns, moment, luxon, and dayjs in the package-lock and node_modules.

---

I think that we should be careful optimizing for yarn 2. As far as I understand it, it's still unclear if it won't create another Python 2 vs. Python 3. Yarn 2 adoption seems slow even with yarn 1 under a subdomain:

https://www.similarweb.com/website/yarnpkg.com/?competitors=classic.yarnpkg.com

[eps1lon]

I think that we should be careful optimizing for yarn 2.

We're not.

[dmtrKovalenko]

Sorry, I completely missed this issue 😞

The fix is available in v2.10.8. Make sure that you need to manually update and lock the version

[oliviertassinari]

Great, thanks :)