Developed a new rails app with ruby3.0 and rails 6.1.0.
Linter in the atom editor throws an error saying rbenv: version `ruby-3.0.0'is not installed.
Since it is necessary to insert ruby-3.0.0 in rbenv, execute the following command.
$ brew update
(It took time ...)
$ brew upgrade rbenv ruby-build
Reference: Update mac ruby with rbenv -Qiita
Then the following error.
==> Installing ruby-build
Error: Your Xcode does not support macOS 11.
It is either outdated or was modified.
Please update your Xcode or delete it if no updates are available.
Xcode can be updated from the App Store.
Error: An exception occurred within a child process:
SystemExit: exit
Manually install the latest Command Line Tools from More Software Downloads -Apple Developer.
Reference: Error: Your Xcode does not support macOS 11 \ .0 . What to do when it appears
After that, the following command again.
$ brew upgrade rbenv ruby-build
Error:
homebrew-core is a shallow clone.
homebrew-cask is a shallow clone.
To `brew update`, first run:
...
I got an error, but it seems to be installed.
$ rbenv install --list
...
3.0.0
...
It's in.
$ rbenv install 3.0.0
...
$ ruby -v
ruby 3.0.0p0 (2020-12-25 revision 95aff21468) [x86_64-darwin20]
success.