fubar'd a ruby installation on ubuntu, need helping purging it for reinstall

i originally followed these steps to get a RoR environmentgoing: https://help.ubuntu.com/community/RubyOnRails

that worked. then i put 1.9.2 on here. then i decided i want the original setup, did a "whereis rub开发者_开发知识库y" and deleted those directories manually.

that fubar'd my ruby installation. i can't use the repository to what i originally had. how can i purge ruby from completely and start fresh?

right now the specific error is this:

/usr/lib/ruby/1.8/rubygems.rb:11:in `require': no such file to load -- thread (LoadError)
        from /usr/lib/ruby/1.8/rubygems.rb:11
        from /usr/bin/gem1.8:8:in `require'
        from /usr/bin/gem1.8:8
tipu@tipu_ubuntu:~$

You're not giving enough real information to be specific, but this is what I'd try:

1. Use apt-search to locate Ruby 1.8.7 for your OS version.
2. Using apt-get, uninstall that version so you're back to what APT thinks is a clean slate.
3. Again using apt-get, reinstall that version so you're back to what APT thinks is a normal installation.

From that point, I would STOP messing with the system Ruby, and instead use RVM to manage and install any new Ruby and gems installations into RVM's ~/.rvm sandbox.

To follow up on the Tin Man's answer:

I wrote a guide to installing Ruby and Rails on Ubuntu which you may find useful for getting this all peachy again.

Hope it helps!

You need to reinstall libruby1.8. I'm pretty sure that will take care of it. I had exactly the same problem.