为我的SBT自动插件项目设置交叉编译

我正在写一个SBT自动插件。这是我的身材。sbt文件

lazy val foo = (project in file(".")).settings(
   name := "foo",
   sbtPlugin := true,
   organization := "com.foo",
   crossScalaVersions = Seq("2.11.8", "2.12.4")
)

但我发现了错误

overloaded method value settings with alternatives:
  (ss: sbt.Def.SettingsDefinition*)sbt.Project <and>
  => Seq[sbt.Def.Setting[_]]
 cannot be applied to (sbt.Def.Setting[String], sbt.Def.Setting[Boolean], sbt.Def.Setting[String], crossScalaVersions: Seq[String])
lazy val foo = (project in file(".")).settings(
                                                         ^
[error] sbt.compiler.EvalException: Type error in expression
[error] sbt.compiler.EvalException: Type error in expression
[error] Use 'last' for the full log.
Project loading failed: (r)etry, (q)uit, (l)ast, or (i

我的目标是 sbt publish 我发布了两个jar文件。一个用于scala 2.11,另一个用于scala 2.12