Hadoop 0.20 is part of the Hadoop 1.0 line
Blarg. Ok, this is just me being stupid. Blah blah, old hadoop versioning, blah blah.
Which part feels glued on?
So, when we released 1.5, we started this practice of having the hadoop-1 and hadoop-2 profile which compiled against "good" versions of Hadoop for each line (read as: most recent "stable-ish"). Presently in 1.5 and beyond, this gives us hadoop-1->1.2.1 and hadoop-2->2.2.0.
With the introduction of these profiles back in the 1.4 series, which previously only knew about 0.20.203.0, it's the same but different. Suddenly, if someone knows what we do in almost two major releases (1.5 and 1.6), and perform the same action (-Dhadoop.profile=1.0), they aren't going to compile against 1.2.1. It just doesn't sit right to me for 1) the 5th point release to suddenly have different build action than the previous 4, and 2) equivalently named build actions that do different things.
That being said, I'm not even sure I like the patch I attached here to clarify things (pretty much why I didn't just commit it). I'm not sure what would be best. Like you said, with hadoop-0.20 being a part of "hadoop 1", but the "hadoop 1" profile using a version of hadoop in the 1.x series in 1.5, we're going to stomp on some approach we previously took. I haven't come up with anything that seems more straightforward yet.