Having issues when running "source ../env.sh; webpack --watch --progress"

[gillytron]

when executing source ../env.sh; webpack --watch --progress
I get the following output:

One CLI for webpack must be installed. These are recommended choices, delivered as separate packages:
 - webpack-cli (https://github.com/webpack/webpack-cli)
   The original webpack full-featured CLI.
We will use "yarn" to install the CLI via "yarn add -D".
Do you want to install 'webpack-cli' (yes/no): yarn add -D

I then run 'yarn add -D webpack-cli'

Installing 'webpack-cli' (running 'yarn add -D webpack-cli')...
yarn add v1.13.0
warning package-lock.json found. Your project contains lock files generated by tools other than Yarn. It is advised not to mix package managers in order to avoid resolution inconsistencies caused by unsynchronized lock files. To clear this warning, remove package-lock.json.
[1/5] 🔍  Validating package.json...
error app@1.0.0: The engine "node" is incompatible with this module. Expected version "9.x". Got "11.6.0"
error Found incompatible module
info Visit https://yarnpkg.com/en/docs/cli/add for documentation about this command.
undefined

however, there's seems to be some package incompatibilities with node. Can please some advise on how to overcome this issue?

thanks

[vincentroman]

run npm install webpack@3.11.0 with sudo permission or run sudo apt install webpack in the app directory

[roryscot]

@BishopMildert This is a simple indication that you have a package-lock.json, which means you have npm installed as a package manager in addition to yarn (which uses yarn.lock). This is not an issue with stream-react-example as far as I can tell.