Use an older version of Rails with Rails 6 installed

Question

Thank you this community for getting me started on the right path. Specifying rails version to use when creating a new application gets me close, but the differing ruby version is what is throwing me off. I'm running into an error after running rails new that I'm not sure where to begin to resolve it. I gather from the error that my command is missing a parameter, but I can't determine what it is.

Any advice?

I would like to create a rails 5.2.6 project and I'm finding consistent responses elsewhere indicating that my approach to getting a rails project created with a specific version is to: install the rails gem with gem install rails -v 5.2.6 create a new rails project, specifying the rails version with rails _5.2.6 new appName

I think I'm on to it. Did a specific google search for compatibility of Ruby 3 with Rails 5 and appears this is the likely problem.

I've now run 'rvm install 2.7.4' then 'rvm use 2.7.4' but still seems to be using ruby 3 in the command. The new error:

user@ubuntudev:~/railsprojects$ rails _5.2.6_ new rpapitest
/home/user/.rbenv/versions/3.0.0/lib/ruby/3.0.0/rubygems.rb:281:in `find_spec_for_exe': can't find gem railties (= 5.2.6) with executable rails (Gem::GemNotFoundException)
    from /home/user/.rbenv/versions/3.0.0/lib/ruby/3.0.0/rubygems.rb:300:in `activate_bin_path'
    from /home/user/.rbenv/versions/3.0.0/bin/rails:23:in `<main>'

Answer 1

如果您安装了rbenv global 2.7.4请尝试使用rbenv global 2.7.4