Replying to sebastic:

The .zo zoo-services get installed in /usr/lib/cgi-bin alongside zoo_loader.cgi, but they aren't CGI executables and shouldn't be installed in the cgi-bin directory.

Private shared libraries should be installed in /usr/lib/zoo-project, see: ​Filesystem Hierarchy Standard: /usr/lib : Libraries for programming and packages

For the .zo and their corresponding .zcfg files, it can be achieved by setting servicePath in the [main] section. Note also, that Knut has added the libPath parameter to the same section, to let you define the location of your .zo files. I think that combining both options may solve the issue.

The .zcfg & main.cfg configuration files are likewise installed in the cgi-bin directory where they don't belong. Configuration files should be installed in /etc/zoo-project, see: ​Filesystem Hierarchy Standard: /etc : Host-specific system configuration

For the main.cfg, following a request relayed by Angelos, we have ​added a specific --with-etc-dir option to define the location of the main.cfg file.

These FHS violations are problematic to get the zoo-project Debian package accepted into the Debian & Ubuntu archives for which there is much stricter quality control than for PPAs (e.g. OSGeo-Live & UbuntuGIS).