Flink Upgrade SBT Assembly Merge Strategy

We decided to upgrade Flink to 1.6.1. As we updated the code, it was running fine on the development machine. I realize that I started getting build issues as soon as I pushed out to source control. It was picked up by the Teamcity build agent and it threw this error:

Actually we were using sbt assembly and we found that it is reproducible on our machines too.

So the natural solution was to just pick one log4j.properties file and try to atleast get it to build:

It did get us through the issue but started getting another error:

So we just added flink-avro dependency to sbt file and the issue was fixed.
https://ci.apache.org/projects/flink/flink-docs-master/dev/batch/connectors.html#avro-support-in-flink