Error at creating .html files with middleman-imageoptim

[ikuwow]

The build fails with the option activate :imageoptim, :pngout => false, :svgo => false.

$ rm -rf build/* && bundle exec middleman build
...
      create  build/javascripts/css-lazyload-1d67c53c.js
      create  build/javascripts/image_modal-d04b55fb.js
      create  build/javascripts/ga_tracking_code-61244895.js
       error  build/2015/05/30/index.html
       error  build/entry/php-cyberterro/index.html
       error  build/entry/lt-middleman/index.html
       error  build/entry/i2cssh/index.html
...
There were errors during this build, re-run with `middleman build --verbose` to see the full exception.

But when i build second time, it doesn't fail...

$ bundle exec middleman build
...
   identical  build/javascripts/css-lazyload-1d67c53c.js
   identical  build/javascripts/image_modal-d04b55fb.js
   identical  build/javascripts/ga_tracking_code-61244895.js
      create  build/2015/05/30/index.html
      create  build/entry/php-cyberterro/index.html
      create  build/entry/lt-middleman/index.html
      create  build/entry/i2cssh/index.html
...

Of cource, build succeeds without the option activate :imageoptim.

With --verbose I get an error message super: no superclass methodget_source_file' for #Middleman::Imageoptim::ManifestResource:0x00000002a0e9c8`.

For the details:
https://travis-ci.org/ikuwow/query_ok/jobs/100811676