I currently have set up Grails 2.3.0 and 2.3.11 inside /opt
directory. How I avoid re-installing by making GVM recognize them as existing candidates?
Move each of the directories to ~/.gvm/grails/<version>
(e.g. from /opt/grails-2.4.3
to ~/.gvm/grails/2.4.3
) and symlink those back to /opt
... or vice versa.
EDIT for sdkman
sdkman replaced GVM. use ~/.sdkman
instead of ~/.gvm