Such a response is only valid in http 1.0, not http 1.1.In this regard rack won't help you much, as it isn't trying to provide for that case.Have you considered not including this middleware for these requests?
#<Rack::ContentLength:0x000055d0e32f7f60
@app=
#<Rack::Chunked:0x000055d0e32f7fb0
@app=
#<Rack::TempfileReaper:0x000055d0e2a07db0
@app=#<LazyAuth::App:0x000055d0e315e910>>>>
#<LazyAuth::App:0x000055d0e315e910>