Your ruby should be most likely installed with readline support if you had the packages from rvm requirements
installed.
You can verify that readline is installed by running:
rvm use 1.9.3
find $MY_RUBY_HOME -name readline.so | xargs ldd
From what I see in the responses a proper flow has to be repeated:
rm -rf $rvm_path/usr/
rvm get head
rvm remove 1.9.3
rvm install 1.9.3 --debug
If you still can not get it working - please make double sure you repeat the above steps, do not add additional flags or switches, make sure to clean up /etc/rvmrc
and ~/.rvmrc
from extra compilation flags. if it all fails provide output of the rvm install 1.9.3 --debug
command.