如何在编译Build.scala时设置SBT使用的scalacOptions？

$reload
[info] Loading global plugins from /Users/xxx/.sbt/0.13/plugins
[info] Loading project definition from /Users/xxx/yyy/zzz/project
[info] Compiling 1 Scala source to /Users/xxx/yyy/zzz/project/target/scala-2.10/sbt-0.13/classes...
[warn] there were 3 deprecation warning(s); re-run with -deprecation for details
[warn] there were 1 feature warning(s); re-run with -feature for details
[warn] two warnings found

我尝试过的事情

>将scalacOptions = Seq(“ – unchecked”,“ – feature”)添加到build.sbt.我希望在Build.scala编译之前加载它.
> Build.scala中已经有scalacOptions = Seq(….,“ – enablehecked”,“ – feature”)
>尝试在重新加载之前设置scalacOptions但它似乎被丢弃

$;set scalacOptions ++= Seq("-feature","-deprecated") ;reload
[info] Defining zzz/*:scalacOptions
[info] The new value will be used by zzz/compile:scalacOptions
[info] Reapplying settings...
[info] Set current project to zzz (in build file:/Users/xxx/yyy/zzz/)
[info] Loading global plugins from /Users/xxx/.sbt/0.13/plugins
[info] Loading project definition from /Users/xxx/yyy/zzz/project
[info] Compiling 1 Scala source to /Users/xxx/yyy/zzz/project/target/scala-2.10/sbt-0.13/classes...
[warn] there were 3 deprecation warning(s); re-run with -deprecation for details
[warn] there were 1 feature warning(s); re-run with -feature for details
[warn] two warnings found
[warn] Discarding 1 session setting.  Use 'session save' to persist session settings.

通过大量的血汗,我能够找到被弃用的警告的原因,但我找不到功能警告的原因.