Problems building ANTLR v4 from source using ant : [java] error(7): cannot find or open file: *.g

[dims...@gmail.com]

Hello,
I was trying to build ANTLR version 4 from source, as I downloaded it from the official website, but I cannot do it using ant. I downloaded the antlr-3.5-complete-no-st3.jar to the /lib folder as build.xml says, but when I run ant it returns:
[mkdir] Created dir: /../antlr/antlr4-master/build/generated-sources/antlr3/org/antlr/v4/parse [java] error(7): cannot find or open file: *.g

BUILD FAILED /../antlr/antlr4-master/build.xml:108: The following error occurred while executing this line: /../antlr/antlr4-master/build.xml:84: Java returned: 1

I am on a MacBook running OSX 10.8.2
Is there anything else I have to do in order to have a successful compilation using ant?

Thanks in advance,
Dimos