Got the error below doing an "ant jar". Looks like the 1.6 Mac compiler needs a little more memory that whatever compiler you're using. Upping the memory to 256m on line 104 of core/build.xml resolved the issue.

compile_main:
[javac] Compiling 1431 source files to /Users/dustin/proj/quickfixj/core/target/classes/main
[javac]
[javac]
[javac] The system is out of resources.
[javac] Consult the following stack trace for details.
[javac] java.lang.OutOfMemoryError: Java heap space
[javac] at com.sun.tools.javac.util.Position$LineMapImpl.build(Position.java:139)
[javac] at com.sun.tools.javac.util.Position.makeLineMap(Position.java:63)
[javac] at com.sun.tools.javac.parser.Scanner.getLineMap(Scanner.java:1105)
[javac] at com.sun.tools.javac.main.JavaCompiler.parse(JavaCompiler.java:512)
[javac] at com.sun.tools.javac.main.JavaCompiler.parse(JavaCompiler.java:550)
[javac] at com.sun.tools.javac.main.JavaCompiler.parseFiles(JavaCompiler.java:801)
[javac] at com.sun.tools.javac.main.JavaCompiler.compile(JavaCompiler.java:727)
[javac] at com.sun.tools.javac.main.Main.compile(Main.java:353)
[javac] at com.sun.tools.javac.main.Main.compile(Main.java:279)
[javac] at com.sun.tools.javac.main.Main.compile(Main.java:270)
[javac] at com.sun.tools.javac.Main.compile(Main.java:69)
[javac] at com.sun.tools.javac.Main.main(Main.java:54)

BUILD FAILED
./build.xml:36: The following error occurred while executing this line:
./build.xml:27: The following error occurred while executing this line:
./core/build.xml:80: The following error occurred while executing this line:
./core/build.xml:85: The following error occurred while executing this line:
./core/build.xml:104: Compile failed; see the compiler error output for details.