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:~$

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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.

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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!

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