jython: FTBFS: NoClassDefFoundError: org/stringtemplate/v4/STGroup

Imported from Debian bug http://bugs.debian.org/796437:

Source: jython
Version: 2.5.3-6
Severity: serious
Justification: fails to build from source
Tags: sid
User: <email address hidden>
Usertags: ftbfs
X-Debbugs-CC: <email address hidden>

Dear Maintainer,

The package fails to build:

clean:

prepare-output:
    [mkdir] Created dir: /jython-2.5.3/build/classes
    [mkdir] Created dir: /jython-2.5.3/build/gensrc/org/python/antlr
    [mkdir] Created dir: /jython-2.5.3/build/exposed
    [mkdir] Created dir: /jython-2.5.3/dist

antlr_gen:
     [java] Exception in thread "main" java.lang.NoClassDefFoundError: org/stringtemplate/v4/STGroup
     [java] at org.antlr.Tool.getRootGrammar(Tool.java:619)
     [java] at org.antlr.Tool.process(Tool.java:478)
     [java] at org.antlr.Tool.main(Tool.java:98)
     [java] Caused by: java.lang.ClassNotFoundException: org.stringtemplate.v4.STGroup
     [java] at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
     [java] at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
     [java] at java.security.AccessController.doPrivileged(Native Method)
     [java] at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
     [java] at java.lang.ClassLoader.loadClass(ClassLoader.java:425)
     [java] at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
     [java] at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
     [java] ... 3 more

BUILD FAILED
/jython-2.5.3/build.xml:498: Java returned: 1

Full build log:
https://reproducible.debian.net/rb-pkg/unstable/amd64/jython.html

-- System Information:
Debian Release: stretch/sid
APT prefers unstable
APT policy: (500, 'unstable')
Architecture: amd64 (x86_64)

Kernel: Linux 3.19.0-23-generic (SMP w/8 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)