Issues installing ActiveTcl with rbenv

Question

ActiveTcl installed properly. Then,I tried:

CONFIGURE_OPTS="--with-tcl-dir=/opt/ActiveTcl-8.6 --enable-pthread" rbenv install 1.9.3-p429

Which resulted in "BUILD FAILED".

Now, no Ruby version will install. I'm using rbenv and never had trouble before.

I just want to experiment with TK and Ruby, but because of rbenv, special configurations to paths are necessary, or "require 'tk'" will not work.

How can I undo the damage I've done with my misuse of CONFIGURE_OPTS? And how can I set up ActiveTcl with rbenv properly?

Per request, here is my "gem env" output:

RubyGems Environment:
  - RUBYGEMS VERSION: 2.0.6
  - RUBY VERSION: 2.0.0 (2013-06-27 patchlevel 247) [x86_64-linux]
  - INSTALLATION DIRECTORY: /home/clyde/.rbenv/versions/2.0.0-p247/lib/ruby/gems/2.0.0
  - RUBY EXECUTABLE: /home/clyde/.rbenv/versions/2.0.0-p247/bin/ruby
  - EXECUTABLE DIRECTORY: /home/clyde/.rbenv/versions/2.0.0-p247/bin
  - RUBYGEMS PLATFORMS:
    - ruby
    - x86_64-linux
  - GEM PATHS:
     - /home/clyde/.rbenv/versions/2.0.0-p247/lib/ruby/gems/2.0.0
     - /home/clyde/.gem/ruby/2.0.0
  - GEM CONFIGURATION:
     - :update_sources => true
     - :verbose => true
     - :backtrace => false
     - :bulk_threshold => 1000
     - "install" => "--no-ri --no-rdoc"
     - "update" => "--no-ri --no-rdoc"
     - "gem" => "--no-ri --no-rdoc"