more specific error when dependencies of a derived setting are undefined
more specific error when dependencies of a derived setting are undefined

mdedetrich/sbt,jkinkead/sbt,dansanduleac/sbt,xuwei-k/xsbt,xeno-by/old-scalameta-sbt,xuwei-k/xsbt,mdedetrich/sbt,sbt/sbt,mdedetrich/sbt,xeno-by/old-scalameta-sbt,jaceklaskowski/sbt,pocketberserker/sbt,mdedetrich/sbt,dyx/sbt,twitter-forks/sbt,dyx/sbt,dyx/sbt,jaceklaskowski/sbt,Duhemm/compiler-bridge,twitter-forks/sbt,xeno-by/old-scalameta-sbt,xeno-by/old-scalameta-sbt,xeno-by/old-scalameta-sbt,xuwei-k/xsbt,dyx/sbt,jaceklaskowski/sbt,dyx/sbt,Duhemm/sbt,twitter-forks/sbt,sbt/sbt,sbt/sbt,sbt/sbt,adriaanm/sbt,pdalpra/sbt,jaceklaskowski/sbt,jaceklaskowski/sbt,jkinkead/sbt,xuwei-k/xsbt,mdedetrich/sbt,mdedetrich/sbt,twitter-forks/sbt,xeno-by/old-scalameta-sbt,jkinkead/sbt,jasonchaffee/sbt,twitter-forks/sbt,Duhemm/sbt,mdedetrich/sbt,jkinkead/sbt,som-snytt/xsbt,sbt/sbt,sbt/sbt,Sciss/sbt,jkinkead/sbt,corespring/sbt,sbt/sbt,xuwei-k/xsbt