我是新的scala和sbt构建文件。在介绍性教程中，通过sbt spark软件包插件将spark依赖项添加到scala项目应该是直截了当的，但我发现以下错误：

[error] (run-main-0) java.lang.NoClassDefFoundError: org/apache/spark/SparkContext

请提供资源，以了解更多关于什么可能是驱动错误，因为我想了解过程更彻底。
代码：

trait SparkSessionWrapper {

  lazy val spark: SparkSession = {
    SparkSession
      .builder()
      .master("local")
      .appName("spark citation graph")
      .getOrCreate()
  }

  val sc = spark.sparkContext

}

import org.apache.spark.graphx.GraphLoader

object Test extends SparkSessionWrapper {

  def main(args: Array[String]) {
    println("Testing, testing, testing, testing...")

    var filePath = "Desktop/citations.txt"
    val citeGraph = GraphLoader.edgeListFile(sc, filepath)
    println(citeGraph.vertices.take(1))
  }
}

插件.sbt

resolvers += "bintray-spark-packages" at "https://dl.bintray.com/spark-packages/maven/"

addSbtPlugin("org.spark-packages" % "sbt-spark-package" % "0.2.6")

build.sbt—正在工作。为什么librarydependencies运行/工作？

spName := "yewno/citation_graph"

version := "0.1"

scalaVersion := "2.11.12"

sparkVersion := "2.2.0"

sparkComponents ++= Seq("core", "sql", "graphx")

libraryDependencies ++= Seq(
  "org.apache.spark" %% "spark-core" % "2.2.0",
  "org.apache.spark" %% "spark-sql" % "2.2.0",
  "org.apache.spark" %% "spark-graphx" % "2.2.0"
)

build.sbt—不工作。希望它能正确编译和运行

spName := "yewno/citation_graph"

version := "0.1"

scalaVersion := "2.11.12"

sparkVersion := "2.2.0"

sparkComponents ++= Seq("core", "sql", "graphx")

额外的解释+资源链接，以了解更多关于sbt构建过程，jar文件，以及任何其他可以帮助我加快速度的东西！