Scala 2.11 is end of life and there are no plans to make a new 2.11 release. The last time a new Scala 2.11 release came out was 2.11.12 at the end of 2017. We kept publishing Scala 2.11 builds because Apache Spark did not start supporting Scala 2.12 until November 2018, but the latest Spark 3.x releases support only 2.12 and have removed support for 2.11.
A pull request in progress (#422) depends on an open source library (os-lib) which has not published any new Scala 2.11 builds since March 2019. We also may need to stop building on Scala 2.11 before we can update some of our dependencies to newer major versions (
Modify the build infrastructure to stop building on Scala 2.11. Also remove some code written only for 2.11 support.