(This is a message from last week that didn't reach the list) Hi, I've just pushed bug 28489 that is adding a new "lib" directory. It needs to be added to the apache config, and new koha-testing-docker images have been published. The error: couldn't load CGI::Session::Serialize::yamlxs: Can't locate CGI/Session/Serialize/yamlxs.pm in @INC (you may need to install the CGI::Session::Serialize::yamlxs module) The KTD solution: `docker-compose pull` A workaround (if you are not using ktd): In your apache config, add the lib directory: SetEnv PERL5LIB "/kohadevbox/koha:/kohadevbox/koha/lib" That's not enough, for the CLI scripts (and tests), you will need to adjust PERL5LIB as well In koha-testing-docker, edit .env and replace the PERL5LIB line with: PERL5LIB=/kohadevbox/koha:/kohadevbox/koha/lib:/kohadevbox/qa-test-tools Cheers, Jonathan