如何让 SBT 子项目具有多个 Scala 版本?

How to have SBT subproject with multiple Scala versions?

我有一个使用 Scala 2.10 的项目和一个使用 Scala 2.11 的项目。它们依赖于一个共同的项目,可以与两者一起编译。

lazy val foo = (project in file("foo")).dependsOn(baz).settings(
  scalaVersion := "2.10.4"
)

lazy val bar = (project in file("bar")).dependsOn(baz).settings(
  scalaVersion := "2.11.4"
)

lazy val baz = (project in file("baz")).settings(
  crossScalaVersions := Seq("2.10.4", "2.11.4"),
  scalaVersion := "2.10.4"
)

然后

$ sbt bar/update
[info] Updating {file:/home/paul/Private/test/}bar...
[info] Resolving baz#baz_2.11;0.1-SNAPSHOT ...
[warn]  module not found: baz#baz_2.11;0.1-SNAPSHOT
[warn] ==== local: tried
[warn]   /home/paul/.ivy2/local/baz/baz_2.11/0.1-SNAPSHOT/ivys/ivy.xml
[warn] ==== public: tried
[warn]   http://repo1.maven.org/maven2/baz/baz_2.11/0.1-SNAPSHOT/baz_2.11-0.1-SNAPSHOT.pom
[info] Resolving jline#jline;2.12 ...
[warn]  ::::::::::::::::::::::::::::::::::::::::::::::
[warn]  ::          UNRESOLVED DEPENDENCIES         ::
[warn]  ::::::::::::::::::::::::::::::::::::::::::::::
[warn]  :: baz#baz_2.11;0.1-SNAPSHOT: not found
[warn]  ::::::::::::::::::::::::::::::::::::::::::::::
[trace] Stack trace suppressed: run last bar/*:update for the full output.
[error] (bar/*:update) sbt.ResolveException: unresolved dependency: baz#baz_2.11;0.1-SNAPSHOT: not found
[error] Total time: 1 s, completed Jan 13, 2015 11:42:51 AM

如何让两个项目都可以使用 baz

Yevgeniy Mordovkin 提出的解决方案,在 baz 项目中声明 crossPaths := false,有效。

您可能会做的另一件事是在命令前添加 +sbt '+ bar/update'。这将为所有已声明的 Scala 版本构建 baz

我有一个类似的设置,并且是这样工作的:

lazy val baz = (project in file("baz")).settings(
  crossScalaVersions := Seq("2.10.4", "2.11.4")
)
lazy val bar = (project in file("bar")).dependsOn(baz).settings(
  scalaVersion := "2.10.4"
)
lazy val foo = (project in file("foo")).dependsOn(baz).settings(
  scalaVersion := "2.11.4"
)

并用

构建
sbt '++ 2.10.4 baz/compile' 'bar/compile' '++ 2.11.4 baz/compile' 'foo/compile'

我为此创建了一个 SBT plugin

project/plugins.sbt

resolvers += Resolver.sonatypeRepo("releases")

addSbtPlugin("com.lucidchart" % "sbt-cross" % "1.0")

build.sbt

lazy val foo = (project in file("foo")).dependsOn(baz_2_10).settings(
  scalaVersion := "2.10.4"
)

lazy val bar = (project in file("bar")).dependsOn(baz_2_11).settings(
  scalaVersion := "2.11.5"
)

lazy val baz = (project in file("baz")).cross

lazy val baz_2_10 = baz("2.10.4")

lazy val baz_2_11 = baz("2.11.5")

还需要几行,但现在一切都按预期编译:sbt foo/compile 有效,sbt bar/compile 有效。

您不必记住独特的命令,您没有来自 crossPath := false 的错误,并且与 ++ 不同,这是可并行化的:sbt compile 将编译 [=17] =]、barbaz 同时使用正确的 Scala 版本。