I'm getting the following when running shadowJar.

gradle shadowJar
:compileJava UP-TO-DATE
:processResources UP-TO-DATE
:classes UP-TO-DATE
:shadowJar FAILED

FAILURE: Build failed with an exception.

• What went wrong:
  Execution failed for task ':shadowJar'.

  The value of a manifest attribute must not be null (Key=Main-Class).

• Try:
  Run with --stacktrace option to get the stack trace. Run with --info or --debug
  option to get more log output.

BUILD FAILED

Total time: 6.362 secs

Gradle file has a manifest with a Main-Class key. http://pastebin.com/WVVdsbeu

Other gradle operations run as expected. Any ideas?