Q: Symbol 'type shapeless.LeftFolder' is missing from the classpath Quick help out on this. During compilation I get the following set of errors ;
Error:(38, 21) Symbol 'type shapeless.HListerAux' is missing from the classpath.
This symbol is required by 'value spray.routing.directives.ParamDefMagnet2.hla'.
Make sure that type HListerAux is in your classpath and check for conflicting dependencies with `-Ylog-classpath`.
A full rebuild may help if 'ParamDefMagnet2.class' was compiled against an incompatible version of shapeless.
          parameter('id) { id =>

Error:(38, 21) Symbol 'type shapeless.Poly.Case2' is missing from the classpath.
This symbol is required by 'method spray.routing.directives.ParamDefMagnet2.MapReduce.from'.
Make sure that type Case2 is in your classpath and check for conflicting dependencies with `-Ylog-classpath`.
A full rebuild may help if 'ParamDefMagnet2.class' was compiled against an incompatible version of shapeless.Poly.
          parameter('id) { id =>

Error:(38, 21) Symbol 'type shapeless.PrependAux' is missing from the classpath.
This symbol is required by 'value spray.routing.directives.ParamDefMagnet2.MapReduce.ev'.
Make sure that type PrependAux is in your classpath and check for conflicting dependencies with `-Ylog-classpath`.
A full rebuild may help if 'ParamDefMagnet2.class' was compiled against an incompatible version of shapeless.
          parameter('id) { id =>

Error:(38, 21) Symbol 'type shapeless.HListerAux' is missing from the classpath.
This symbol is required by 'value spray.routing.directives.ParamDefMagnet2.hla'.
Make sure that type HListerAux is in your classpath and check for conflicting dependencies with `-Ylog-classpath`.
A full rebuild may help if 'ParamDefMagnet2.class' was compiled against an incompatible version of shapeless.
          parameter('id) { id =>

Although, in summary, the problem is with 'shapeless', a library which I have already included as a dependency as (with the resolvers), 
resolvers ++= Seq(
  Resolver.sonatypeRepo("releases"),
  Resolver.sonatypeRepo("snapshots")
)

libraryDependencies ++= Seq(
  "com.chuusai" %% "shapeless" % "2.3.2"
) 

I would appreciate a suitable recommendation as a fix. 

A: I know how to solve it, I met this problem before.
It is the problem of Shapeless Versions, read the following scentence carefully, and you will solve this problem.
Shapeless Versions
If you want to use shapeless as well as spray-routing in your application you need to select the version of spray(-routing) that was built against the shapeless release which you'd like to use.
For shapeless 1.2.4 you should use spray 1.1.4, 1.2.4 or 1.3.4 and the spray-routing module.
shapeless 2.0.0 is not supported any more.
For shapeless 2.3.0 you should use spray 1.3.4 (Scala 2.10 or Scala 2.11) and the spray-routing-shapeless23 module instead of spray-routing.
libraryDependencies ++= "io.spray" %% "spray-routing-shapeless23" % "1.3.4",

