Building app does not work with yarn

[vaclavbohac]

Deploying a react app with yarn.lock fails to compile the app as yarn ignores the NPM_CONFIG_PRODUCTION flag and omits the dev dependencies necessary to run the webpack.

There's a simple workaround as all you need to do is to delete yarn.lock file from the project and the build scripts will fall back to the npm (https://github.com/heroku/heroku-buildpack-nodejs/blob/v93/bin/compile#L54). But that't not what you really want to do

[gaearon]

Should the be filed with Yarn?

[mars]

The underlying Node buildpack recently added Yarn support, so I imagine this should not be too difficult to get working 🤞

How does one for devDeps to install with Yarn? Looks like NODE_ENV needs to be set to development during build in the inner buildpack.

I'm traveling for the holidays and will not have a chance to investigate immediately.

[mars]

It's possible that setting that config/env var manually will prove the fix:

heroku config:set NODE_ENV=development

# then redeploy
git push heroku master

If that works, then I will update the underlying buildpack compile to automate this step during npm build

[laduke]

Didn't deploy something for a couple days and this happened to me too. Thanks for the thread.

heroku config:set NODE_ENV=development

worked for me. Not sure what the proper yarn solution would be.

[Aadmaa]

"heroku config:set NODE_ENV=development" worked for me too. For clarity ... if folks are starting a brand new web app right now and you are looking at this -- https://blog.heroku.com/deploying-react-with-zero-configuration -- for deployment instructions, add the step as shown below, or deployment to Heroku fails.

npm install -g create-react-app
create-react-app my-app
cd my-app
git init
heroku create -b https://github.com/mars/create-react-app-buildpack.git
git add .
git commit -m "react-create-app on Heroku"

// ADD to your process here:
heroku config:set NODE_ENV=development

git push heroku master
heroku open

[mars]

Just released support for yarn in this buildpack, so no special configuration is required to use yarn.

[gaearon]

Thank you!