Tell RVM which patch level you mean by "1.8.7" or "1.9.3"

When you download or upgrade RVM it has a hardcoded notion which patch level it considers to be "1.9.3".

This can give you errors like "ruby-1.9.3-p392 is not installed" even if you have another Ruby 1.9.3 that will do.

The solution is to define an alias:

rvm alias create 1.9.3 ruby-1.9.3-p385

Fuzzy matching

Another solution is to use rvm with the fuzzy flag, as stated by mpapis Show archive.org snapshot .

rvm use --fuzzy .

This will make rvm more intelligent in the Ruby selection. To always do fuzzy matching, run this:

echo rvm_fuzzy_flag=1 >> ~/.rvmrc