Handling Error: Found interface org.apache.hadoop.mapreduce.TaskAttemptContext, but class was expected
The answer in the link I posted in the question above asked to compile against Hadoop 2.0 library. Incidentally the post Hadoop 1.0, instead of using one single Hadoop Core jar for compilation, two (or maybe more) different jars are to be used.
I used:hadoop-common-2.0.2-alpha.jarhadoop-mapreduce-client-core-2.0.2-alpha.jar
for compiling my code and after that it ran fine w/o giving the aforementioned error.
For me I found that I was using the wrong version of Hadoop with Avro 1.7.4 (http://www.cloudera.com/content/cloudera/en/documentation/cdh4/v4-2-0/CDH4-Release-Notes/cdh4ki_topic_2_9.html)