“...I've been working since 2008 with Ruby / Ruby on Rails, love a bit of Elixir / Phoenix and learning Rust. I also poke through other people's code and make PRs for OpenSource Ruby projects that sometimes make it. Currently working for InPay who are based in Denmark...”

Rob Lacey
Senior Software Engineer, UK

How do I fix has unmet peer dependency...

…and what does it even mean?

DEBUG [40866a5f] 	yarn install v1.7.0
DEBUG [40866a5f] 	warning package.json: No license field
DEBUG [40866a5f] 	warning No license field
DEBUG [40866a5f] 	[1/4] Resolving packages...
DEBUG [40866a5f] 	[2/4] Fetching packages...
DEBUG [40866a5f] 	info fsevents@1.2.4: The platform "linux" is incompatible with this module.
DEBUG [40866a5f] 	info "fsevents@1.2.4" is an optional dependency and failed compatibility check. Excluding it from installation.
DEBUG [40866a5f] 	[3/4] Linking dependencies...
DEBUG [40866a5f] 	warning "@rails/webpacker > postcss-cssnext@3.1.0" has unmet peer dependency "caniuse-lite@^1.0.30000697".
DEBUG [40866a5f] 	warning " > react-google-maps@9.4.5" has unmet peer dependency "@types/googlemaps@^3.0.0".
DEBUG [40866a5f] 	warning " > react-google-maps@9.4.5" has unmet peer dependency "@types/markerclustererplus@^2.1.29".
DEBUG [40866a5f] 	warning " > react-google-maps@9.4.5" has unmet peer dependency "@types/react@^15.0.0 || ^16.0.0".
DEBUG [40866a5f] 	warning " > webpack-dev-server@2.11.2" has unmet peer dependency "webpack@^2.2.0 || ^3.0.0".
DEBUG [40866a5f] 	warning "webpack-dev-server > webpack-dev-middleware@1.12.2" has unmet peer dependency "webpack@^1.0.0 || ^2.0.0 || ^3.0.0".
DEBUG [40866a5f] 	[4/4] Building fresh packages...
DEBUG [40866a5f] 	Done in 17.33s.

Firstly the licence warning can be removed by making the package private.

{
  "private": true,
  "dependencies": {
    "@rails/webpacker": "3.5",
    "axios": "^0.18.0",
    "babel-preset-react": "^6.24.1",
  /*... and some more ... */
}