Today, I have met a bug of octopress. When you write your blog with number in categories, like “cattegories: [some keyword, 2012]”.
When you type
rake generate. The command will report:
block in write_category_indexes;: undefined method
gsub; for 2012:Fixnum (NoMethodError)
It is caused by your number
Go to line
109. and add a line code:
rake generate again. It will be fine.