$ sh bin/rebuildjar.sh 
    using JAR jar...
    usage: cp [-R [-H | -L | -P]] [-fi | -n] [-apvX] source_file     target_file
           cp [-R [-H | -L | -P]] [-fi | -n] [-apvX] source_file ...     target_directory
    including etherpad JARs...
    using cached JAR-etherpad...
    updating...
    java.io.FileNotFoundException: ../../build/appjet.jar (No such file  or directory)
	at java.io.FileInputStream.open(Native Method)
	at java.io.FileInputStream.<init>(FileInputStream.java:106)
	at sun.tools.jar.Main.run(Main.java:175)
	at sun.tools.jar.Main.main(Main.java:1044)
    done.
    cp: build/appjet.jar: No such file or directory

Anyone got any ideas what I'm doing wrong?