You can clone with
HTTPS or Subversion.
I just installed redis 2.6.7 from source on my OpenBSD 5.2 install. There were any number of warnings. Previously and maybe even this time... the system will likely function, however, these warnings are part of the base mantra of the OpenBSD team and it has proven to remove bugs and the like. It is highly recommended. (If I knew what I was doing I'd do it for you)