I have tried everything I can think of to get this to work, to no avail so here I am requesting suggestions on how to debug.
Firstly, runnning Ubuntu 11.10
I
Ubuntu 12.04 here: the answers here helped, but were also misleading.
If you're using Ubuntu 12.04, DO NOT pkg install readline, with or without --skip-autoreconf. After you've done that, either readline or zlib will be broken no matter what combination of switches you give to rvm install 1.9.3.
To get it to work, do the apt-get install that rvm requirements tells you to do, do a pkg uninstall readline and then do a simple rvm remove 1.9.3; rvm install 1.9.3