I just had to change dependencies in Cassandra for the first time and I think the documentation [1] is out of date.
First I think most of the file edits are in the ".build" directory. Adding jars to the "lib" directory works until calling "ant realclean", so perhaps the instructions should include regenerating the "lib" folder after making the edits. If I am wrong please let me know, otherwise I will open a ticket and update the documentation. [1] https://cassandra.apache.org/_/development/dependencies.html