It appears to depend on the 'pypy' package now. Installing that fixed the issue (though the "'import site' failed" warning is still there).
- Bug#825702: python-pypy.sandbox: Upgrading past... raylu
- Bug#825702: Acknowledgement (python-pypy.s... raylu
- Bug#825702: python-pypy.sandbox: Upgrading... Stefano Rivera
- Bug#825702: marked as done (python-pypy.sa... Debian Bug Tracking System