I'm getting an email on every commit The page build failed with the following error:.

No error is displayed.

Locally the build completes succeffully.

 # jekyll build
Configuration file: none
            Source: /slobodensoftver.mkd
       Destination: /slobodensoftver.mkd/_site
      Generating... done.

One of the steps in https://help.github.com/articles/using-jekyll-with-pages#troubleshooting is
to disable jekyll with .nojekyll.