Installing ebook-convert
ebook-convert is required to generate ebooks (epub, mobi, pdf).
Mac
Download the Calibre app. After moving the calibre.app to your Applications folder create a symbolic link to the ebook-convert tool:
$ sudo ln -s ~/Applications/calibre.app/Contents/MacOS/ebook-convert /usr/bin
You can replace /usr/bin with any directory that is in your $PATH.