Can't push Heroku (missing buildpack?) ImageOptim::BinResolver::Error: Bin resolving errors: remote: pngout worker: `pngout` not found; please provide proper binary or disable this worker

[jasonfb]

The buildpacks on my environment are as follows

=== xyz-app Buildpack URLs
1. https://github.com/jasonfb/heroku-buildpack-cedar14-imagemagick704
2. https://github.com/bobbus/image-optim-buildpack
3. heroku/ruby

when I try to push to my environment with only image_optim, I am able to get through the build successfully. When add this gem

gem 'image_optim_rails'

and bundle install it, then push again to Heroku, I get:

https://gist.github.com/jasonfb/43a8e5aa4a7fe32205948110286a1c9e

[jasonfb]

UPDATE: When I have both gems installed:

gem 'image_optim_rails'
gem 'image_optim_pack'

it works & build cleanly. my app is building against Cedar 14 :sunny:

[jasonfb]

RESOLVED; archived at SO http://stackoverflow.com/questions/42329978/imageoptimbinresolvererror-bin-resolving-errors-remote-pngout-worker-usi

[toy]

That was fast!