apache2-dbg software package provides Apache debugging symbols, 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 apache2-dbg
apache2-dbg is installed in your system.
Make ensure the apache2-dbg package were installed using the commands given below,
$ sudo dpkg-query -l | grep apache2-dbg *
You will get with apache2-dbg package name, version, architecture and description in a table
| Distro | Debian 9 stretch |
| Section | Debug packages |
| Package | apache2-dbg |
| Version | 2.4.23-5 |
| Description | Apache debugging symbols |
| Sub Section | debug |