Ruby Gems many versions or bug? [FIXED]

hi i follow this guide:
i use the last part (Building from Source)

because when i have trying install the Ruby gems

i had this error:
ERROR: Error installing net-ldap:
net-ldap requires Ruby version >= 1.9.3.

so i installed the version: ruby 2.2.2p95

for fix this error i try to install the gems and i have the same error with oneadmin


when i did the same command but with the root user i successful installed the gems.

i think that the problem was result but i run the command again with the oneadmin user and i have the same version error

you know what is this issue?