如何在sbt多项目中定义编译设置？

Question

我正在尝试使用sbt multi-project配置一个新的Scala版本。我想使用sbt-protoc，尤其是ScalaPB，它需要以下配置设置：

Compile / PB.targets := Seq(
  scalapb.gen() -> (Compile / sourceManaged).value
)

现在的问题是如何在多项目中正确地应用sbt.librarymanagement.Configurations.Compile配置。我使用的是Scala 2.13和sbt 1.4.7。

我当前的build.sbt

Compile / PB.targets := Seq(
  scalapb.gen() -> (Compile / sourceManaged).value
)

lazy val commonSettings = List(
  scalaVersion := scala212,
  scalacOptions ++= Seq(
    "utf8",
    "-Ypartial-unification"
  )
)

lazy val core = (project in file("core"))
  .settings(
    commonSettings,
    name := "twirp4s-core",
    crossScalaVersions := Seq(scala212, scala213),
    libraryDependencies ++= Seq(
      catsCore,
      circeCore,
      circeGeneric,
      circeParser,
      http4sDsl,
      http4sCirce
    ),
    addCompilerPlugin(betterMonadicForPlugin),
  )

lazy val root = (project in file("."))
  .aggregate(core)
  .settings(
    name := "twirp4s-root",
    libraryDependencies += scalaTest % Test,
    skip in publish := true
  )

当我尝试编译我的项目时，编译器说：

[info] Protobufs files found, but PB.targets is empty.

Answer 1

正如你已经知道的，@Seth在评论中建议，将Compile / PB.targets移动到core.settings中是可行的。这是您应该使用的build.sbt：

lazy val commonSettings = List(
  scalaVersion := scala212,
  scalacOptions ++= Seq(
    "utf8",
    "-Ypartial-unification"
  )
)

lazy val core = (project in file("core"))
  .settings(
    commonSettings,
    name := "twirp4s-core",
    crossScalaVersions := Seq(scala212, scala213),
    libraryDependencies ++= Seq(
      catsCore,
      circeCore,
      circeGeneric,
      circeParser,
      http4sDsl,
      http4sCirce
    ),
    addCompilerPlugin(betterMonadicForPlugin),
    Compile / PB.targets := Seq(
      scalapb.gen() -> (Compile / sourceManaged).value
    )
  )

lazy val root = (project in file("."))
  .aggregate(core)
  .settings(
    name := "twirp4s-root",
    libraryDependencies += scalaTest % Test,
    skip in publish := true
  )