Files not being created on Heroku

Question

I host my Jekyll-based blog (github code) on a Heroku cedar stack.

I build the jekyll files through my Rakefile:

namespace :assets do
  desc 'Precompile assets'
  task :precompile do
    sh "bundle exec sass --update _scss:_css --style compressed"
    sh "bundle exec jekyll"
  end
end

This outputs the files into a _site directory, which is where Rack will serve the files from.

This has been working for over a year, and is working fine on the currently live version of my blog (released a fortnight ago):

$ heroku run ls _site                                                                                                 
Running `ls _site` attached to terminal... up, run.9360
2012  404  apple-touch-icon.png  back-end  css          front-end  index.html  politics    public-domain.txt  rss.xml
2013  410  assets                config    favicon.ico  go.sh      personal    postsbytag  robots.txt         sitemap.xml

However, whenever I try to release anything now, or release the same version of the code to a new app, the _site directory doesn't seem to be created:

$ git push git push [email protected]:robinwinslow-dev.git
...
http://robinwinslow-dev.herokuapp.com deployed to Heroku
...
$ heroku run ls _site --app robinwinslow-dev
Running `ls _site` attached to terminal... up, run.2577
ls: cannot access _site: No such file or directory

And the site shows:

Internal Server Error
No such file or directory - _site/404/index.html

Does anyone know why this would have changed? Has anything changed in Heroku? Or have I suddenly done something stupid?

Answer 1

I don't know why this ever worked in the first place, because Heroku has a read-only file system. The solution would be to compile your site including all assets locally, check them into Git and then push the complete _site directory to Heroku.