This is a configuration of the RubySpec set of specifications -
http://rubyspec.org. RubySpec is the specifications, and MSpec is the tool to
run them.

Thanks to Brian Shirai and others who have worked on RubySpec.

At the moment we have only configured the version 1.9 specs, and we only run
language and command line specs.

In the `specs` directory (everything we do here will be in the `specs`
directory), you need to clone the MSpec and RubySpec Git repositories:

    $ git clone https://github.com/rubyspec/mspec.git
    $ git --git-dir=mspec/.git --work-tree=mspec checkout 1343524a06466b7aa0c90798b7894454c8abce0f
    $ git clone https://github.com/rubyspec/rubyspec.git
    $ git --git-dir=rubyspec/.git --work-tree=rubyspec checkout 926e356b268fe32c67bec43a21565d727360a89b

Then you can run MSpec to run RubySpec. We can run all of the harness in our
implementation, not just as an executable under test.

    $ ./rubytruffle mspec/bin/mspec run -t ./rubytruffle --config rubytruffle.mspec --excl-tag fails