As I can see in recent releases of akka-http, successor of spray, spray-routing's approach of using shapeless HList was replaced in favor of self-included Tuple What is the motivation for this transformation? Has this done just for self-inclusion or pure Tuples without intermediate generic transformations  to HLists are practically more efficient or simple? 
What is the reason behing Tuples instead of HList in akka-http
refactoring;akka;generic programming
On https://gitter.im/akka/dev, Konrad Malawski writes:It's aboutthe horrible error messages that one gets if things go wrong with HListsnot depending on shapeless, so people can use whatever version of shapeless that they want toit's totally possible to build a HList based version of those methods and give it to people as a library, would be fun if someone would maintain itwe needed a javadsl, so we'd have to build the tuple style anyway