how to install ruby 3.0.0 in macOS Catalina - ruby

Question

Now I am using this command to install ruby 3.0.0 in macOS Catalina:
rvm get stable
rvm install ruby-3.0.0
shows this error:
$ rvm install ruby-3.0.0
Searching for binary rubies, this might take some time.
No binary rubies available for: osx/10.15/x86_64/ruby-3.0.0.
Continuing with compilation. Please read 'rvm help mount' to get more information on binary rubies.
Checking requirements for osx.
Installing requirements for osx.
Updating system - please wait
Failed to update Homebrew, follow instructions at
https://docs.brew.sh/Common-Issues
and make sure `brew update` works before continuing.
Error running 'requirements_osx_brew_update_system ruby-3.0.0',
please read /Users/dolphin/.rvm/log/1615433437_ruby-3.0.0/update_system.log
Requirements installation failed with status: 1.
(base)
Is it possible to install ruby using rvm in macOS Catalina 10.15.7? what should I do to make it work? where should I find the binary? This is my rvm info:
$ rvm -v
rvm 1.29.12 (latest) by Michal Papis, Piotr Kuczynski, Wayne E. Seguin [https://rvm.io]
(base)
and then I check the log:
$ tail -f /Users/dolphin/.rvm/log/1615433437_ruby-3.0.0/update_system.log
+rvm_error:2> rvm_pretty_print stderr
+rvm_pretty_print:2> case auto (0|no)
+rvm_pretty_print:2> case auto (1|auto)
+rvm_pretty_print:8> case xterm-256color (dumb|unknown)
+rvm_pretty_print:12> case stderr (stdout)
+rvm_pretty_print:12> case stderr (stderr)
+rvm_pretty_print:14> [[ -t 2 ]]
+rvm_pretty_print:14> return 1
+rvm_error:4> printf %b $'Failed to update Homebrew, follow instructions at\n\n https://docs.brew.sh/Common-Issues\n\nand make sure `brew update` works before continuing.\\n'
+requirements_osx_brew_update_system:27> return 1
wqq^C
(base)
and runs brew update command:
$ brew update
Already up-to-date.
(base)
seems the rvm update failed but successed in command line env.