我收到错误there were 15 feature warning(s); re-run with -feature for details：
$ /usr/local/sbt/bin/sbt
[info] Loading project definition from /home/alex/Documents/projects/my_app123/project
[info] Set current project to sbt-android (in build file:/home/alex/Documents/projects/my_app123/)
> compile -feature
[error] Expected end of input.
[error] compile -feature
[error] ^
> sbt-version
[info] 0.12.4
> compile
[warn] Credentials file /home/alex/.ivy2/.credentials does not exist
[info] Compiling 20 Scala sources to /home/alex/Documents/projects/my_app123/target/scala-2.10/sbt-0.12/classes...
[error] there were 15 feature warning(s); re-run with -feature for details
[error] one error found
[error] (compile:compile) Compilation failed
[error] Total time: 27 s, completed 01 12, 15 1:20:12 PM
在 build.sbt
中scalaVersion := "2.10.4"
我无法找出该错误是什么，因为它没有说明，即使我将sbt作为$ /usr/local/sbt/bin/sbt -feature运行。
$ /usr/local/sbt/bin/sbt -feature
[info] Loading project definition from /home/alex/Documents/projects/my_app123/project
[info] Set current project to sbt-android (in build file:/home/alex/Documents/projects/my_app123/)
$
这是JDK 1.7
错误是什么，我该如何解决？
更新：
build.sbt
scalacOptions in ThisBuild ++= Seq("-unchecked", "-deprecation")
或在sbt本身：
> set scalacOptions in ThisBuild ++= Seq("-unchecked", "-deprecation")
错误保持不变。
答案 0 :(得分：8)
我没有机会每天使用sbt，所以这只是为了确认链接答案中的建议：
$ sbt
[info] Set current project to Compiler options (in build file:/home/apm/tmp/sbtwarn/)
> compile
[info] Compiling 1 Scala source to /home/apm/tmp/sbtwarn/target/scala-2.11/classes...
[warn] there was one feature warning; re-run with -feature for details
[warn] one warning found
[success] Total time: 4 s, completed Jan 12, 2015 9:45:17 AM
> set scalacOptions in ThisBuild ++= Seq("-feature")
[info] Defining {.}/*:scalacOptions
[info] The new value will be used by compile:scalacOptions
[info] Reapplying settings...
[info] Set current project to Compiler options (in build file:/home/apm/tmp/sbtwarn/)
> compile
[info] Compiling 1 Scala source to /home/apm/tmp/sbtwarn/target/scala-2.11/classes...
[warn] /home/apm/tmp/sbtwarn/src/main/scala/Sample.scala:6: postfix operator head should be enabled
[warn] by making the implicit value scala.language.postfixOps visible.
[warn] This can be achieved by adding the import clause 'import scala.language.postfixOps'
[warn] or by setting the compiler option -language:postfixOps.
[warn] See the Scala docs for value scala.language.postfixOps for a discussion
[warn] why the feature should be explicitly enabled.
[warn] Console println (List(1,2,3) head)
[warn] ^
[warn] one warning found
[success] Total time: 1 s, completed Jan 12, 2015 9:45:46 AM
答案 1 :(得分：4)
你应该添加
scalacOptions += "-feature"
到您的build.sbt并在您的sbt控制台运行（或重新启动它）时执行重新加载。
或者，如果您只想为单个会话设置它，而在sbt控制台中，您可以编写set scalacOptions += "-feature"，此设置立即应用，无需重新加载或重新启动sbt控制台。