Using tango with dub

[albert-j via Digitalmars-d-learn]

I am trying to use Tango in a dub project because I need a 
HashSet. I added Tango as a dependency to the dub.json, but now 
dub gives me a bunch of depreciation warnings and a few errors, 
like

../../../.dub/packages/tango-1.0.3_2.068/tango/tango/util/log/Log.d(349,51): 
Error: undefined identifier '__va_argsave', did you mean struct 
'__va_argsave_t'?
What am I missing?