gem react-rails fails to install react on rails 6

Question

I'm trying to set up on my app the gem 'react-rails', following https://github.com/reactjs/react-rails.

bundle install
rails webpacker:install
rails webpacker:install:react

He's set up the

app/javascript/components/ directory for your React components
 ReactRailsUJS setup in app/javascript/packs/application.js
 app/javascript/packs/server_rendering.js for server-side rendering

but when I launch

rails generate react:install

it sends this warning

Running via Spring preloader in process 34494
       exist  app/javascript/components
   identical  app/javascript/components/.keep
warning " > @babel/[email protected]" has unmet peer dependency "@babel/core@^7.0.0-0".                                                                                           
warning "@babel/preset-react > @babel/[email protected]" has unmet peer dependency "@babel/core@^7.0.0-0".                                                 
warning "@babel/preset-react > @babel/[email protected]" has unmet peer dependency "@babel/core@^7.0.0-0".                                                          
warning "@babel/preset-react > @babel/[email protected]" has unmet peer dependency "@babel/core@^7.0.0-0".                                              
warning "@babel/preset-react > @babel/[email protected]" has unmet peer dependency "@babel/core@^7.0.0-0".                                                     
warning "@babel/preset-react > @babel/[email protected]" has unmet peer dependency "@babel/core@^7.0.0-0".                                                   
warning "@babel/preset-react > @babel/[email protected]" has unmet peer dependency "@babel/core@^7.0.0-0".                                             
warning "@babel/preset-react > @babel/plugin-transform-react-jsx > @babel/[email protected]" has unmet peer dependency "@babel/core@^7.0.0-0".                               
warning " > [email protected]" has unmet peer dependency "webpack@^4.0.0 || ^5.0.0".                                                                                        
warning "webpack-dev-server > [email protected]" has unmet peer dependency "webpack@^4.0.0".                                                                             
File unchanged! The supplied flag value not found!  app/javascript/packs/application.js
   identical  app/javascript/packs/server_rendering.js

And my localhost rendering doesn't work, and sends me :

undefined method `react_component' for #<#<Class:0x00007f9270ab7e80>:0x00007f9270ecd448>

Has anyone some hint ?

Answer 1

I've resolved part of it : I managed by quitting and coming back to my Terminal. But now it can't read the react_component properly :

27:        <h1><%= react_component ("Coucou", { greeting: "Pipi" }) %></h1>

app/views/layouts/application.html.erb:27: syntax error, unexpected ',', expecting ')'
app/views/layouts/application.html.erb:27: syntax error, unexpected '}', expecting ')'