[Distutils] setuptools: bug in run_script

[Ian Bicking]

Ian Bicking wrote:
> Ben Bangert encountered a problem where
> pkg_resources.WorkingSet.run_script didn't work; from line 407:
> 
>         self.require(requires)[0].run_script(script_name, ns)
> 
> If all the packages are already loaded for some reason, then
> self.require() returns [].

Looking at it, I think self.require(requires)[0] would only work if the
package was installed multi-version.  When all the packages are
activated by default, of course require() should return nothing.