You can clone with
HTTPS or Subversion.
Arachni should integrate with a static binary analysis tool so it can verify its findings with a binary analysis or source code static analysis tool.
I don't disagree in general but Arachni's goal is to be a good web app scanner.
Although integration with SASTs would be cool my dev focus cannot shift to that at the moment.
However, I'll leave this ticket open as a reminder for future development endeavours.
Closing this since nothing relevant came up in 2 years and plugins like vector_feed make highly customized audits possible and allow such integration for anyone who requires it.