Build: jfreeciv FAILED to build

The Build for jfreeciv failed on 2002-12-01 at 09:46:18. The build log is below:

Buildfile: build.xml

init:
     [echo] jfreeciv build started December 1 2002 at 0947

copyfiles:
     [copy] Copying 1 file to /home/buildman/build/jfreeciv/class
     [copy] Copying 15 files to /home/buildman/build/jfreeciv/class/org/freeciv/util/po
     [copy] Copied 1 empty directory to /home/buildman/build/jfreeciv/class/org/freeciv/util/poja
     [copy] Copying 151 files to /home/buildman/build/jfreeciv/class/org/freeciv/common/data
     [copy] Copied 1 empty directory to /home/buildman/build/jfreeciv/class/org/freeciv/common/data

src:
    [javac] Compiling 304 source files to /home/buildman/build/jfreeciv/class
    [javac] /home/buildman/build/jfreeciv/src/org/freeciv/client/handler/PHBeforeNewYear.java:6: cannot resolve symbol
    [javac] symbol  : class Assert  
    [javac] location: package common
    [javac] import org.freeciv.common.Assert;
    [javac]                           ^
    [javac] /home/buildman/build/jfreeciv/src/org/freeciv/client/handler/PHCityNameSuggestion.java:5: cannot resolve symbol
    [javac] symbol  : class Assert  
    [javac] location: package common
    [javac] import org.freeciv.common.Assert;
    [javac]                           ^
    [javac] /home/buildman/build/jfreeciv/src/org/freeciv/client/handler/PHNewYear.java:6: cannot resolve symbol
    [javac] symbol  : class Assert  
    [javac] location: package common
    [javac] import org.freeciv.common.Assert;
    [javac]                           ^
    [javac] /home/buildman/build/jfreeciv/src/org/freeciv/client/handler/PHRemoveUnit.java:5: cannot resolve symbol
    [javac] symbol  : class Assert  
    [javac] location: package common
    [javac] import org.freeciv.common.Assert;
    [javac]                           ^
    [javac] 4 errors

BUILD FAILED
file:/home/buildman/build/jfreeciv/build.xml:102: Compile failed; see the compiler error output for details.

Total time: 1 minute 28 seconds