Bundler fails when there is more gemspecs in one directory

[botanicus]

I'm usually using two gemspecs for my gems, one is for standard release and one is for prerelease. It might sound weird, but I have good reasons for this layout. This is an example:

• http://github.com/botanicus/nake/blob/master/nake.gemspec
• http://github.com/botanicus/nake/blob/master/nake.pre.gemspec

This is what I'm getting with both stable bundler & bundler from GitHub:

Calculating dependencies...
You have to have changelog gem installed for post install message
ERROR:  While executing gem ... (Errno::ENOENT)
    No such file or directory - nake.gemspec

It works when I remove the nake.pre.gemspec.