为什么我的 sourceDirectories 设置在 sbt 中无效？答案

【问题标题】：Why does my sourceDirectories setting have no effect in sbt?为什么我的 sourceDirectories 设置在 sbt 中无效？
【发布时间】：2014-12-03 17:26:58
【问题描述】：

我正在阅读 SBT Getting Started 指南。该页面以sourceDirectories 设置为例。为了自己尝试，我将以下内容放入我的 build.sbt 文件中，用于基本的“hello world”项目。

sourceDirectories in Compile := Seq(file("other"))

（附加+= 或++= 也不起作用。）

我在<base-dir>/other 和<base-dir>/src/main/scala 中有源文件。我跑了sbt 并输入了compile。它忽略了设置：

> compile
[info] Compiling 1 Scala source to /Learning/Scala/proj1/target/scala-2.9.2/classes...
[error] /Learning/Scala/proj1/src/main/scala/hello.scala:7: not found: value Foo
[error]     println(Foo.foo)

Foo 对象在 other 源目录的 foo.scala 中定义。

我错过了什么？

【问题讨论】：

标签： sbt

【解决方案1】：

tl;dr The answer by @schleichardt 是有效的 - 您需要将以下内容添加到 build.sbt 文件中：

unmanagedSourceDirectories in Compile += file("other")

解释归结为检查compile 任务的依赖关系。使用inspect tree compile 找出它们。

[proj1]> inspect tree compile
[info] compile:compile = Task[sbt.inc.Analysis]
[info]   +-compile:compile::compileInputs = Task[sbt.Compiler$Inputs]
[info]   | +-compile:scalacOptions = Task[scala.collection.Seq[java.lang.String]]
[info]   | +-compile:sources = Task[scala.collection.Seq[java.io.File]]
[info]   | +-*/*:sourcePositionMappers = Task[scala.collection.Seq[scala.Function1[xsbti.Position, scala.Option[xsbti.Position]]]]
[info]   | +-*/*:maxErrors = 100
[info]   | +-*:compilers = Task[sbt.Compiler$Compilers]
[info]   | +-compile:compile::streams = Task[sbt.std.TaskStreams[sbt.Init$ScopedKey[_ <: Any]]]
[info]   | | +-*/*:streamsManager = Task[sbt.std.Streams[sbt.Init$ScopedKey[_ <: Any]]]
[info]   | |
[info]   | +-compile:incCompileSetup = Task[sbt.Compiler$IncSetup]
[info]   | +-*/*:compileOrder = Mixed
[info]   | +-compile:dependencyClasspath = Task[scala.collection.Seq[sbt.Attributed[java.io.File]]]
[info]   | +-compile:classDirectory = target/scala-2.10/classes
[info]   | +-*/*:javacOptions = Task[scala.collection.Seq[java.lang.String]]
[info]   |
[info]   +-compile:compile::streams = Task[sbt.std.TaskStreams[sbt.Init$ScopedKey[_ <: Any]]]
[info]     +-*/*:streamsManager = Task[sbt.std.Streams[sbt.Init$ScopedKey[_ <: Any]]]
[info]

如您所见，该任务依赖于compile:sources 任务。该任务又依赖于使用compile:unmanagedSourceDirectories 设置的compile:unmanagedSources 任务。

[proj1]> inspect tree compile:sources
[info] compile:sources = Task[scala.collection.Seq[java.io.File]]
[info]   +-compile:unmanagedSources = Task[scala.collection.Seq[java.io.File]]
[info]   | +-compile:unmanagedSourceDirectories = List(/Users/jacek/sandbox/stackoverflow/proj1/src/main/scala, /Users/jacek/sandbox/stackoverflow/proj1/src/main/java, /Users/..
[info]   | | +-compile:javaSource = src/main/java
[info]   | | | +-compile:sourceDirectory = src/main
[info]   | | |   +-*:sourceDirectory = src
[info]   | | |   | +-*:baseDirectory = /Users/jacek/sandbox/stackoverflow/proj1
[info]   | | |   |   +-*:thisProject = Project(id: proj1, base: /Users/jacek/sandbox/stackoverflow/proj1, aggregate: List(), dependencies: List(), configurations: List(compile..
[info]   | | |   |
[info]   | | |   +-compile:configuration = compile
[info]   | | |
[info]   | | +-compile:scalaSource = src/main/scala
[info]   | | | +-compile:sourceDirectory = src/main
[info]   | | |   +-*:sourceDirectory = src
[info]   | | |   | +-*:baseDirectory = /Users/jacek/sandbox/stackoverflow/proj1
[info]   | | |   |   +-*:thisProject = Project(id: proj1, base: /Users/jacek/sandbox/stackoverflow/proj1, aggregate: List(), dependencies: List(), configurations: List(compile..
[info]   | | |   |
[info]   | | |   +-compile:configuration = compile
[info]   | | |
[info]   | | +-*:baseDirectory = /Users/jacek/sandbox/stackoverflow/proj1
[info]   | |   +-*:thisProject = Project(id: proj1, base: /Users/jacek/sandbox/stackoverflow/proj1, aggregate: List(), dependencies: List(), configurations: List(compile, runt..
[info]   | |
[info]   | +-*/*:excludeFilter = sbt.SimpleFileFilter@7ced8ea7
[info]   | +-*:baseDirectory = /Users/jacek/sandbox/stackoverflow/proj1
[info]   | +-*/*:unmanagedSources::includeFilter = sbt.SimpleFilter@1beb6bba
[info]   | +-*/*:sourcesInBase = true
[info]   |
[info]   +-compile:managedSources = Task[scala.collection.Seq[java.io.File]]
[info]     +-compile:sourceGenerators = List()
[info]

compile:unmanagedSourceDirectories 设置引用“非托管源目录，其中包含手动创建的源。”

[proj1]> inspect compile:unmanagedSourceDirectories
[info] Setting: scala.collection.Seq[java.io.File] = List(/Users/jacek/sandbox/stackoverflow/proj1/src/main/scala, /Users/jacek/sandbox/stackoverflow/proj1/src/main/java, /Users/jacek/sandbox/stackoverflow/proj1/other)
[info] Description:
[info]  Unmanaged source directories, which contain manually created sources.
[info] Provided by:
[info]  {file:/Users/jacek/sandbox/stackoverflow/proj1/}proj1/compile:unmanagedSourceDirectories
[info] Defined at:
[info]  (sbt.Defaults) Defaults.scala:161
[info]  /Users/jacek/sandbox/stackoverflow/proj1/build.sbt:1
[info] Dependencies:
[info]  compile:javaSource
[info]  compile:scalaSource
[info]  *:baseDirectory
[info] Reverse dependencies:
[info]  compile:unmanagedSources
[info]  compile:sourceDirectories
[info] Delegates:
[info]  compile:unmanagedSourceDirectories
[info]  *:unmanagedSourceDirectories
[info]  {.}/compile:unmanagedSourceDirectories
[info]  {.}/*:unmanagedSourceDirectories
[info]  */compile:unmanagedSourceDirectories
[info]  */*:unmanagedSourceDirectories
[info] Related:
[info]  test:unmanagedSourceDirectories

该设置是scala.collection.Seq[java.io.File] 类型，并且要将元素附加到seq，您可以使用+= 方法。

话虽如此，build.sbt 文件应该如下：

unmanagedSourceDirectories in Compile += (baseDirectory / "other").value

您不必使用baseDirectory 设置，但它使基本目录明确。

【讨论】：

感谢您的详尽回答。我认为它会帮助其他人。就我而言，我已经放弃了 SBT，我希望永远不会回来。
哦，加油@RobN，sbt 太难了，所以你必须把它写在你的简历上，才能在面试时在其他“普通”开发人员中大放异彩 :-) 说真的，sbt 与make, ant, maven, gradle, buildr 值得花时间去学习。您使用什么构建工具？
@Jacek Laskowski...我曾经在 pyspark 上工作，特别是在 Scala 和 SBT 方面遇到了很多困难。您能否就以下问题提出您宝贵的建议。 stackoverflow.com/questions/63084177/…谢谢

【解决方案2】：

你可以试试这个：

unmanagedSourceDirectories in Compile += file("other")

【讨论】：