This tiny tool will look up epics which you provide in the config file in the jira API, get all child issues and their subtasks, git --grep your git repository for those issues and print out some statistics.
cd src/main/resources
cp application.properties.example application.properties
vim application.properties
cd ../../..
sbt runscanning 3 epics...changed files..commits..changed lines..done.
issues: 53
commits pushed: 266
files changed: 2178
lines changed: 323819