FTBFS: compile errors

During rebuild testing:

cd . && /usr/lib/jvm/default-java/bin/java -classpath /usr/share/ant/lib/ant.jar:/usr/share/ant/lib/ant-launcher.jar:/usr/share/java/commons-collections3.jar:/usr/share/java/jetty6.jar:/usr/share/java/jetty6-util.jar:/usr/share/java/ecj.jar:/usr/share/java/servlet-api-2.5.jar:/usr/share/java/junit.jar:/usr/lib/jvm/default-java/lib/tools.jar -Dant.home=/usr/share/ant org.apache.tools.ant.Main -DartifactVersion=1.6.4 -buildfile ./debian/build.xml
Buildfile: ./debian/build.xml

build:
  [taskdef] Could not load definitions from resource net/sf/antcontrib/antlib.xml. It could not be found.

build:
  [taskdef] Could not load definitions from resource net/sf/antcontrib/antlib.xml. It could not be found.

core:
  [taskdef] Could not load definitions from resource net/sf/antcontrib/antlib.xml. It could not be found.

build.alldeps.jar:
    [mkdir] Created dir: /build/buildd/gwt-1.6.4/build/out/dev/core

build:
    [mkdir] Created dir: /build/buildd/gwt-1.6.4/build/out/dev/core/bin-dummy
[gwt.javac] Compiling 1 source file to /build/buildd/gwt-1.6.4/build/out/dev/core/bin-dummy
    [mkdir] Created dir: /build/buildd/gwt-1.6.4/build/out/dev/core/bin
[gwt.javac] Compiling 3 source files to /build/buildd/gwt-1.6.4/build/out/dev/core/bin
[gwt.javac] Compiling 630 source files to /build/buildd/gwt-1.6.4/build/out/dev/core/bin
[gwt.javac] /build/buildd/gwt-1.6.4/dev/core/src/com/google/gwt/dev/SwtHostedModeBase.java:31: package org.eclipse.swt does not exist
[gwt.javac] import org.eclipse.swt.SWT;
[gwt.javac] ^
[gwt.javac] /build/buildd/gwt-1.6.4/dev/core/src/com/google/gwt/dev/SwtHostedModeBase.java:32: package org.eclipse.swt.events does not exist
[gwt.javac] import org.eclipse.swt.events.DisposeEvent;
[gwt.javac] ^
[gwt.javac] /build/buildd/gwt-1.6.4/dev/core/src/com/google/gwt/dev/SwtHostedModeBase.java:33: package org.eclipse.swt.events does not exist
[gwt.javac] import org.eclipse.swt.events.DisposeListener;
[gwt.javac] ^
...