How to add `--legacy-peer-deps` flag to npm install when doing a build

[bluelobster7]

As many know there has been some issues lately with the upgrade to react 17 where some packages will have react 16 as dependency while others have react 17. I have this in my project for a couple packages, and it causes npm install to fail unless the --legacy-peer-deps flag is added. Is there anyway I can add this flag to the npm install phase of the eas build?

[wodin]

The easiest workaround is to use node version 14.

EAS Build fails with unknown error

we updated the default node version from 14 to 16 today, so if you did not specify an explicit node version before then it would be updated in your project. this may be the cause of the issue for you. you can set the node version to “14.18.1” in your build profile to use the previously default version. Configuring EAS Build with eas.json - Expo Documentation

[bluelobster7]

Yup this worked. Thanks!

[wodin]

Here’s how you can add --legacy-peer-deps:

How to config EAS build use yarn or npm

hi there! eas build will use yarn if you have a yarn.lock file. if you use npm and want to use --legacy-peer-deps, you can set this in your .npmrc. you can create a .npmrc file in your project with the legacy-peer-deps option set or run npm config set legacy-peer-deps true in an eas-build-pre-install hook