icingaweb2 vs PHP 8 compatibility failure

[Joel N. Weber II]

On Ubuntu 23.04, when clicking on a specific service to get details, the web browser shows this backtrace; back in 18.04, clicking on this was useful to get the full output of a plugin to understand exactly what the plugin was reporting:

Uncaught ValueError: Unknown format specifier "!" in /usr/share/icingaweb2/modules/eventdb/library/Eventdb/ProvidedHook/Monitoring/EventdbActionHook.php:171
Stack trace:
#0 /usr/share/icingaweb2/modules/eventdb/library/Eventdb/ProvidedHook/Monitoring/EventdbActionHook.php(171): sprintf()
#1 /usr/share/icingaweb2/modules/eventdb/library/Eventdb/ProvidedHook/Monitoring/EventdbActionHook.php(104): Icinga\Module\Eventdb\ProvidedHook\Monitoring\EventdbActionHook::getObjectKey()
#2 /usr/share/icingaweb2/modules/eventdb/library/Eventdb/ProvidedHook/Monitoring/ServiceActions.php(13): Icinga\Module\Eventdb\ProvidedHook\Monitoring\EventdbActionHook::getActions()
#3 /usr/share/icingaweb2/modules/monitoring/library/Monitoring/Hook/ServiceActionsHook.php(50): Icinga\Module\Eventdb\ProvidedHook\Monitoring\ServiceActions->getActionsForService()
#4 /usr/share/icingaweb2/modules/monitoring/library/Monitoring/Hook/ObjectActionsHook.php(21): Icinga\Module\Monitoring\Hook\ServiceActionsHook->getActionsForObject()
#5 /usr/share/icingaweb2/modules/monitoring/application/controllers/ServiceController.php(60): Icinga\Module\Monitoring\Hook\ObjectActionsHook->getNavigation()
#6 /usr/share/icingaweb2/modules/monitoring/application/controllers/ServiceController.php(71): Icinga\Module\Monitoring\Controllers\ServiceController->getServiceActions()
#7 /usr/share/icingaweb2/library/vendor/Zend/Controller/Action.php(507): Icinga\Module\Monitoring\Controllers\ServiceController->showAction()
#8 /usr/share/php/Icinga/Web/Controller/Dispatcher.php(76): Zend_Controller_Action->dispatch()
#9 /usr/share/icingaweb2/library/vendor/Zend/Controller/Front.php(937): Icinga\Web\Controller\Dispatcher->dispatch()
#10 /usr/share/php/Icinga/Application/Web.php(290): Zend_Controller_Front->dispatch()
#11 /usr/share/php/Icinga/Application/webrouter.php(105): Icinga\Application\Web->dispatch()
#12 /usr/share/icingaweb2/public/index.php(4): require_once('...')
#13 {main}
thrown

Essentially the same problem existed with 22.10 though I did not get around to reporting this while I still had this running on 22.10; it's not clear to me whether the syntax used is documented as being expected to work in any version of PHP in the PHP documentation. It seems Debian 11 is still on PHP 7 whereas Ubuntu 23.04 uses PHP 8, so perhaps there may not have been much of a push to test icingaweb2 with PHP 8 yet.

# apt-cache policy icingaweb2
icingaweb2:
  Installed: 2.11.4-2
  Candidate: 2.11.4-2
  Version table:
 *** 2.11.4-2 500
        500 http://us.archive.ubuntu.com/ubuntu lunar/universe amd64 Packages
        500 http://us.archive.ubuntu.com/ubuntu lunar/universe i386 Packages
        100 /var/lib/dpkg/status

# lsb_release -rd
No LSB modules are available.
Description: Ubuntu 23.04
Release: 23.04