ProGuard mówi numer wersji nieobsługiwany klasa [52,0] (maksymalnie 51,0, Java 1.7) z SBT-PROGUARD

Question

jestem na Mac OS X 10.9.2 i SBT 0.13.3-SNAPSHOT (zbudowany ze źródeł) , Java 8 i wtyczka sbt-proguard 0.2.2.

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) 

projekt/plugins.sbt

addSbtPlugin("com.typesafe.sbt" % "sbt-proguard" % "0.2.2") 

Kiedy wpadłem proguard:proguard w SBT shell to wysadzili z następującym wyjątkiem:

[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 

Dlaczego może być przyczyną tego błędu?

Answer 1

Wygląda na to, że ProGuard, a tym samym sbt-proguard, nie obsługuje jeszcze środowiska Java 8 i zmienia wersję Java użytą w skrypcie, aby uruchomić sbt.

[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) 
... 

To z poniższej wersji Java 7:

$ /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) 

Answer 2

Jest możliwe, aby zaktualizować wersję PROGUARD że SBT-PROGUARD używa poprzez zmianę klucza proguardVersion w build.sbt na ustawienie nowszy niż 5,0, np

ProguardKeys.proguardVersion in Proguard := "5.2.1" 

Patrz: https://github.com/sbt/sbt-proguard/issues/5