Remove GEM_PATH line 93 from runspecs?

I am using rbenv 0.4.0 (current) on OSX.  When I run the runspecs command, it produces this error:
<pre>$ ./runspecs --quick
./runspecs:93:in `<main>': undefined method `split' for nil:NilClass (NoMethodError)</pre>

Line 93 is:
<pre>    ENV['GEM_PATH'] = ENV['GEM_PATH'].split(':').reject{|dir| dir =~ %r{/rbenv}}.join(':')</pre>

The problem is that ENV['GEM_PATH'] is nil.  According to the comment above this section of the code, it applies to rbenv, but rbenv doesn't set that variable.  I searched the rbenv project for GEM_PATH and got no hits, so I don't think it ever uses that environment variable: https://github.com/sstephenson/rbenv/search?q=GEM_PATH&type=Code

When I comment out the line, runspecs runs to completion.

Can this line just be removed?