Not compatible with PHP 8

[paulrobertlloyd]

Possibly an issue with Savant3 dependency not being compatible with PHP 8. Running the application produces this error:

Fatal error: Uncaught ValueError: func_get_arg(): Argument #1 ($position) must be less than the number of the arguments passed to the currently executed function in 
/app/vendor/saltybeagle/savant3/Savant3.php:901

Stack trace:
#0 /app/vendor/saltybeagle/savant3/Savant3.php(901): func_get_arg(1)
#1 /app/vendor/p3k/slim-savant/Savant.php(74): Savant3->assign(Array)
#2 /app/vendor/slim/slim/Slim/View.php(255): Slim\Extras\Views\Savant->render('layout.php', Array)
#3 /app/vendor/slim/slim/Slim/View.php(243): Slim\View->fetch('layout.php', NULL)
#4 /app/vendor/slim/slim/Slim/Slim.php(755): Slim\View->display('layout.php')
#5 /app/vendor/p3k/slim-savant/SlimSavant.php(19): Slim\Slim->render('layout.php', Array)
#6 /app/controllers/main.php(5): Slim\Savant\render('index')
#7 [internal function]: {closure}()
#8 /app/vendor/slim/slim/Slim/Route.php(468): call_user_func_array(Object(Closure), Array)
#9 /app/vendor/slim/slim/Slim/Slim.php(1355): Slim\Route->dispatch()
#10 /app/vendor/slim/slim/Slim/Middleware/Flash.php(85): Slim\Slim->call()
#11 /app/vendor/slim/slim/Slim/Middleware/MethodOverride.php(92): Slim\Middleware\Flash->call() 
#12 /app/vendor/slim/slim/Slim/Middleware/PrettyExceptions.php(67): Slim\Middleware\MethodOverride->call()
#13 /app/vendor/slim/slim/Slim/Slim.php(1300): Slim\Middleware\PrettyExceptions->call()
#14 /app/public/index.php(12): Slim\Slim->run()
#15 {main} thrown in /app/vendor/saltybeagle/savant3/Savant3.php on line 901

There may be other such incompatibility issues lurking in dependencies or in the apps own code.

PHP 7.x is no longer maintained and has reached end of life. One way this manifests itself is that versions below v8 are disabled in Brew, and not supported by tools like Nixpicks.