This rbenv plugin resolves rvm MRI Ruby version identifiers. This allows a Ruby version identifier of ruby-2.6 to resolve to the latest version of 2.6 such 2.6.5. This allows compatibility between rvm and rbenv for projects using these identifiers in their .ruby-version files.
Simply clone the repository and the rbenv-whatis dependency into the plugins directory:
mkdir -p $(rbenv root)/plugins
git clone https://github.com/rkh/rbenv-whatis.git $(rbenv root)/plugins/rbenv-whatis
git clone https://github.com/nickpith/rbenv-rvm-mri-versions.git $(rbenv root)/plugins/rbenv-rvm-mri-versions