ant-optional software package provides Java based build tool like make - optional libraries, you can install in your Debian 9 (Stretch) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install ant-optional
ant-optional is installed in your system.
Make ensure the ant-optional package were installed using the commands given below,
$ sudo dpkg-query -l | grep ant-optional *
You will get with ant-optional package name, version, architecture and description in a table
| Distro | Debian 9 stretch |
| Section | Java |
| Package | ant-optional |
| Version | 1.9.7-3 |
| Description | Java based build tool like make - optional libraries |
| Sub Section | Java |