Fails to run, fails to build

[blickly]

1. Download and unzip closure-compiler
2. Try to compile a JS file:

$ java -jar compiler.jar ../editor/svgcanvas.js 
Exception in thread "main" java.lang.UnsupportedClassVersionError: Bad
version number in .class file
    at java.lang.ClassLoader.defineClass1(Native Method)
    at java.lang.ClassLoader.defineClass(ClassLoader.java:676)
    at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:124)
    at java.net.URLClassLoader.defineClass(URLClassLoader.java:260)
    at java.net.URLClassLoader.access$100(URLClassLoader.java:56)
    at java.net.URLClassLoader$1.run(URLClassLoader.java:195)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(URLClassLoader.java:188)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:317)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:280)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:252)
    at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:375)

1. svn co the closure-compiler product
2. try to build: 

$ ant jar
Buildfile: build.xml

compile:
    [mkdir] Created dir:
/Users/jschill1/Documents/closure-compiler/build/classes
    [javac] Compiling 4 source files to
/Users/jschill1/Documents/closure-compiler/build/classes
    [javac]
/Users/jschill1/Documents/closure-compiler/gen/com/google/javascript/jscomp/FunctionInfo.java:9:
cannot access com.google.protobuf.ExtensionRegistry
    [javac] bad class file:
/Users/jschill1/Documents/closure-compiler/lib/protobuf_deploy.jar(com/google/protobuf/ExtensionRegistry.class)
    [javac] class file has wrong version 50.0, should be 49.0
    [javac] Please remove or make sure it appears in the correct
subdirectory of the classpath.
    [javac]       com.google.protobuf.ExtensionRegistry registry) {
    [javac]                          ^
    [javac] 1 error

BUILD FAILED
.../closure-compiler/build.xml:52: Compile failed; see the compiler error
output for details.

Original issue reported on code.google.com by codedread on 2010-01-17 01:24:56

[blickly]

Ok, I'm on Leopard.  Java 6?  huh.

Downloading - please close the issue

Original issue reported on code.google.com by codedread on 2010-01-17 01:44:17

[blickly]

Yeah, sorry about that. I wish Java had some way for us to message version 
incompatibilities, rather than just throwing a strange error.

I'll add the error message to the FAQ.

Original issue reported on code.google.com by Nicholas.J.Santos on 2010-01-17 02:36:41