Rails: Webpack-dev-server has unmet peer dependency - ruby-on-rails

Question

I am currently trying to set up a Rails 6.0.2 application on Ubuntu 18.0.4 using Docker.
I have successfully set up the database using PostgreSQL and I have installed the necessary gems by running the command below:
bundle install
However, when I try to install the node packages using the command below:
yarn install
I get the message below which gives me some concern that something is not right:
warning " > webpack-dev-server#3.10.3" has unmet peer dependency "webpack#^4.0.0 || ^5.0.0".
warning "webpack-dev-server > webpack-dev-middleware#3.7.2" has unmet peer dependency "webpack#^4.0.0".
I have tried a few solutions but it's not working. I need some help. Thank you.

Answer 1

Here's how I solved:
Simply run the command below to upgrade the version of yarn to your desired version:
yarn upgrade webpack#^4.0.0
Note: You can substitute 4.0.0 with the required version for yarn, say 5.0.0.
Another Solution
Add the version of webpack that you want to your package.json file. Here the version of webpack used is 4.43.0:
"devDependencies": {
"webpack": "^4.43.0",
"webpack-dev-server": "^3.11.0"
}
And then run yarn install to install webpack
For Docker Applications only:
Add the command just before the yarn install command in your Dockerfile:
RUN yarn upgrade webpack#^4.0.0 \
yarn install
Reference to this on GitHub: Unmet peer dependencies
That's all.
I hope this helps.

Answer 2

I upgraded packages one at a time but kept getting the same warnings.
So I ran:
yarn upgrade
and next time I ran this all the warnings messages there were there previously had gone away:
yarn install