I just now rebased my blog code on top of the latest commit in master (c977b91) and apparently the latest version doesn't play well with the jekyll_alias_generator.
I have a couple of posts which I've made aliases for, so I don't know if it's just this one specific file with an alias that breaks or if it's many, but here's the error:
jekyll 2.0.3 | Error: Not a directory @ rb_file_s_stat - /home/linduxed/Documents/blog/public/blog/2013/6/29/some-blog-post/index.html/
It could be that the plugin needs to be tweaked to work with Jekyll 2.x, but I wouldn't know.
@linduxed It looks like the jekyll-redirect-from plugin takes care of this same need. Can you try that and let us know if it suits your needs? https://github.com/jekyll/jekyll-redirect-from
For anyone reaching here now, looks like this issue is fixed in the plugin with the commit tsmango/jekyll_alias_generator@ff09231