We're building a rails app into a Docker container, and as part of that in our Dockerfile we:

`RUN bundle exec rake assets:precompile`

This uses sprockets to compile the assets, generates a manifest file into the Docker image, and synchronizes the assets to S3 for exposure on the CDN. Asset synchronization occurs via credentials exposed in the environment of the user running the docker build command.

This works locally, but it appears that this plugin doesn't run the build command in the same environment that the jenkins user runs, nor does it respect the environment variables injected into the workspace by jenkins.

I'm not sure if this is a bug or a feature request, but either way, it'd be cool if this worked.