After install ruby 2.7.1, found capistrano deploy via puma having below error when restart:

/home/web_site/.rbenv/versions/2.7.1/bin/bundle:23:in `load': cannot load such file -- /home/web_site/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/bundler-2.1.4/libexec/bundle (LoadError)

After checking long time found it's just not install the bundler 1.17.3 as pumactl relay on it.

rbenv uninstall 2.6.5
rbenv global 2.7.1
rbenv shell 2.7.1
gem install bundler --default -v "1.17.3"
gem install bundler

Notes, still need after capistrano-bundler release 2.0.