I am having problems building a project using ant build from the command line on one system, but it works on antoher

I am having problems building a project using ant build from the command line on one system, but it works on antoher.

The Java version is 1.7 on both systems. I don't have Eclipse on the system on which it doesn't work.

So, I wonder if ant build uses something from Eclipse while doing ant build, even if I run it from the command line.