Awestruct in Docker Container via Jenkins

Question

I want to use awestruct inside a docker container to build my website. Everything seems to work but at the end I receive a message in Jenkins job: Jenkins Job Error
When I run the docker container directly on the server (not via Jenkins job) with:
docker run -i -t --rm --volume /home/jenkins/workspace/myWebsite :/home/jenkins/myWebsite:Z --name myWebsite_Container mbiarnes/myWebsite:latest /bin/bash
I can access directly the container. I can do a rake setup (rake setup output). But when doing a rake clean build I get an error
I tried nearly everything but I cannot advance. This is my Dockerfile. When doing awestruct --version I get bash: awestruct: command not found
like awestruct is not installed, but in rake setup output you can see that awestruct 0.5.7 is used. Also during the building of docker image I didn't receive any errors and I can see in the logs that awestruct is installed succesfully.