The roadmaps for prior releases e.g. 1.6 2.0 2.1 2.2 were available: 2.2.0 https://issues.apache.org/jira/browse/SPARK-18813
2.1.0 https://issues.apache.org/jira/browse/SPARK-15581 .. It seems those roadmaps were not available per se' for 2.3.0 and later? Is there a different mechanism for that info? stephenb
