I can find "http-proxy-*" variables in .subversion/server to configure SVN to pass through HTTP proxy server. How can SVN be configured to pass through SOCKS proxy server (like TOR)?
Subversion can connect through a HTTP proxy or an SSH tunnel, but it has no idea about SOCKS,
so you need to "SOCKSify" Subversion by capturing all its TCP connects and redirecting them to the SOCKS proxy. This can be done by using ProxyChains.
Have a look at these pages for examples on how to use it: