Hadoop 1.0 is an ancient, and I believe dead, version that certainly nobody should use today. We have a chronic problem on the 0.98 branch with changes tested on only Hadoop 2 later are found to break builds against Hadoop 1, since only 0.94 and 0.98 still support Hadoop 1.x. See https://issues.apache.org/jira/browse/HBASE-12397 as an example. This issue also illustrates that dropping support for 1.0 while retaining support for 1.1 and later versions of Hadoop 1.x can reduce cross-version compatibility complexity for at least the API involved in that issue, and certainly others. This in my opinion is a good thing.
-- Best regards, - Andy Problems worthy of attack prove their worth by hitting back. - Piet Hein (via Tom White)
