我使用的是 Mac OS X 10.9.2 和 sbt 0.13.3-SNAPSHOT (从源代码构建)， Java 8 和 sbt-proguard 0.2.2 插件。
sbt 0.13.3-SNAPSHOT
[jacek]> sbtVersion
[info] 0.13.3-SNAPSHOT
Java 8
$ /Library/Java/JavaVirtualMachines/jdk1.8.0.jdk/Contents/Home/bin/java -version
java version "1.8.0"
Java(TM) SE Runtime Environment (build 1.8.0-b132)
Java HotSpot(TM) 64-Bit Server VM (build 25.0-b70, mixed mode)
项目/plugins.sbt
addSbtPlugin("com.typesafe.sbt" % "sbt-proguard" % "0.2.2")
当我在sbt shell中运行
proguard:proguard时，它因以下异常而爆炸:[sbt-updates]> show proguard:proguard
[info] ProGuard, version 4.9
[info] Reading program directory [/Users/jacek/oss/sbt-updates/target/scala-2.10/sbt-0.13/classes] (filtered)
[info] Reading program jar [/Users/jacek/.ivy2/cache/org.scalaz/scalaz-concurrent_2.10/bundles/scalaz-concurrent_2.10-7.1.0-M6.jar] (filtered)
[info] Reading program jar [/Users/jacek/.sbt/boot/scala-2.10.3/lib/scala-library.jar] (filtered)
[info] Reading program jar [/Users/jacek/.ivy2/cache/org.scalaz/scalaz-core_2.10/bundles/scalaz-core_2.10-7.1.0-M6.jar] (filtered)
[info] Reading program jar [/Users/jacek/.ivy2/cache/org.scalaz/scalaz-effect_2.10/bundles/scalaz-effect_2.10-7.1.0-M6.jar] (filtered)
[info] Reading library jar [/Library/Java/JavaVirtualMachines/jdk1.8.0.jdk/Contents/Home/jre/lib/rt.jar]
[error] Error: Can't read [/Library/Java/JavaVirtualMachines/jdk1.8.0.jdk/Contents/Home/jre/lib/rt.jar] (Can't process class [apple/applescript/AppleScriptEngine.class] (Unsupported class version number [52.0] (maximum 51.0, Java 1.7)))
[trace] Stack trace suppressed: run last proguard:proguard for the full output.
[error] (proguard:proguard) Proguard failed with exit code [1]
[error] Total time: 16 s, completed Apr 19, 2014 2:27:56 PM
为什么可能是错误的原因？
最佳答案
似乎ProGuard以及sbt-proguard尚不支持Java 8，并且更改脚本中使用的Java版本以启动sbt很有帮助。
[sbt-updates]> show proguard:proguard
[info] Compiling 8 Scala sources to /Users/jacek/oss/sbt-updates/target/scala-2.10/sbt-0.13/classes...
[warn] there were 6 feature warning(s); re-run with -feature for details
[warn] one warning found
[info] ProGuard, version 4.9
[info] Reading program directory [/Users/jacek/oss/sbt-updates/target/scala-2.10/sbt-0.13/classes] (filtered)
[info] Reading program jar [/Users/jacek/.ivy2/cache/org.scalaz/scalaz-concurrent_2.10/bundles/scalaz-concurrent_2.10-7.1.0-M6.jar] (filtered)
...
以下版本的是Java 7的:
$ /Library/Java/JavaVirtualMachines/jdk1.7.0_51.jdk/Contents/Home/bin/java -version
java version "1.7.0_51"
Java(TM) SE Runtime Environment (build 1.7.0_51-b13)
Java HotSpot(TM) 64-Bit Server VM (build 24.51-b03, mixed mode)
关于sbt - ProGuard说带有sbt-proguard的不受支持的类版本号[52.0](最大51.0，Java 1.7)，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/23170502/