Spike out mondrian XML/A
You'll need to download derby-foodmart.zip from https://github.com/pentaho/mondrian/blob/0513fbe724619a7c669009b7539bf51d1faaa858/demo/derby/derby-foodmart.zip.
You can't download from github directly so will need to clone the repo or download from Sourceforge and locate the derby-foodmart.zip
Then:
mkdir -p src/main/webapp/WEB-INF/classes/
unzip derby-foodmart.zip -d src/main/webapp/WEB-INF/classes/Given a good JAVA_HOME
run mvn clean compile exec:java