Use the BigProjectLogger :
This logger is designed to make examining the logs of a big build easier, especially those run under continuous integration tools. It
1.When entering a child project, prints its name and directory
2.When exiting a child project, prints its name
3.Includes the name of the project when printing a target
4.Omits logging the names of all targets that have no direct task output
5.Includes the build finished timestamp of the TimeStamp logger
This is useful when using <subant> to build a large project from many smaller projects -the output shows which particular project is building.