I just downloaded the pre-compiled binaries in this post over the binaries on my system worked like a charm. But if you must recompile from git, I would assume you need to delete the existing git clone directory, try "sudo rm -R /usr/local/src/darkcoin" and then rerun your git clone command.
Do we need to also revert this change in p2pool?
"In the file p2pool/data.py, on line 171 change "masternode_payout =
worker_payout / 10" to "masternode_payout = worker_payout / 5"