There is no source tarball for 0.17.0 at http://xpra.org/src/, but from SVN I gather it was released already.
No, the 0.17.x branch has been tagged, 0.17.0 has not been released yet.
I assumed that
/tags/ means tagged versions and branches (if there were any) would be stored in
/branches/. Thanks for clarifying.
this ticket has been moved to: https://github.com/Xpra-org/xpra/issues/1183