The goal of shims is to make Hive compiled with "ant package" to work with any version of hadoop.
However currently it is not working with hadoop 0.17 for a minor issue:
org.apache.hadoop.io.Text.compareTo was inherited (and NOT overriden) from org.apache.hadoop.io.BinaryComparable.compareTo in hadoop 0.18 and above. When compiling Hive by default, we will compile it against hadoop 0.19.0. Java compiler will automatically replace org.apache.hadoop.io.Text.compareTo with org.apache.hadoop.io.BinaryComparable.compareTo in some places, and that caused the problem.