我收到一个错误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"
我无法找出那个错误是什么,因为它没有说,即使我运行sbt as $ /usr/local/sbt/bin/sbt -feature.
$ /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")
或者在sbt本身:
> set scalacOptions in ThisBuild ++= Seq("-unchecked", "-deprecation")
错误保持不变.
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
嘿,它有效!
您应该添加
scalacOptions += "-feature"
到build.sbt并在sbt控制台正在运行（或重新启动）的情况下执行reload。
另外，如果您只想为单个会话设置它，则在sbt控制台中可以写入set scalacOptions += "-feature"，此设置将立即应用，无需重新加载或重新启动sbt控制台。