Already fixed, but filing for tracking purposes.
Fixed as part of 7b256624b8b2 in ruby-main; I'm going to extract the fix from that changeset and backport to
Created attachment 79808 [details]
Attached is a patched module for NB 6.5.1. You need to copy the .jar file to <nb install dir>/ruby2/modules/
(overwrites org-netbeans-modules-ruby-railsprojects.jar, you might want to make a backup of it first).
I should add the you need to restart the IDE after copying the jar.
Pushed the fix, b4e3d8436d56 in release65_fixes.