Cannot compile Vaadin

Win 7, IVY installed, Ant installed, Java 7 installed.

Fresh clone from Git, compilation ends with error:


Property "osgi.extra.package.prefixes" has not been set
     [java]
 Executing 'c:\Program Files\Java\jdk1.7.0_03\jre\bin\java.exe' with arguments:
     [java]
 '-Dvaadin.version=7.0.3-SNAPSHOT'
     [java]
 '-classpath'
     [java]
 'C:\Work\Dev\vaadin-7\buildhelpers\result\classes'
     [java]
 'com.vaadin.buildhelpers.GeneratePackageExports'
     [java]
 'C:\Work\Dev\vaadin-7\buildhelpers\result\lib\vaadin-buildhelpers-7.0.3-SNAPSHOT.jar'
     [java]
 'com/vaadin'
     [java]
 'com/google'
     [java]
 '${osgi.extra.package.prefixes}'
     [java]
 
     [java]
 The ' characters around the executable and arguments are
     [java]
 not part of the command.
     [java]
 Updating manifest in JAR C:\Work\Dev\vaadin-7\buildhelpers\result\lib\vaadin-buildhelpers-7.0.3-SNAPSHOT.jar
     [java]
 Failed to execute 'jar' command. Cannot run program "jar": CreateProcess error=2, Systém nem??e nalézt uvedený soubo

Full log file included…
12887.txt (139 KB)