cachet: php artisan app:install error

Hi,

I’ve setup CentOS 7.4 with PHP 7.2.2 and all the required plugins.

When running php artisan app:install, I get:

Clearing settings cache...
Settings cache cleared!
Backing up database...
Dumping database and uploading...

Successfully dumped mysql, compressed with gzip and store it to local at /var/www/html/Cachet/database/backups/2018-02-07 03.17.51
Backup completed!
Application key [base64:GnohIAUv/ErZPJrIaOHPx4ETgLpkZrXbwd5FE5lNJRU=] set successfully.
Configuration cache cleared!
Configuration cached successfully!
Route cache cleared!
Routes cached successfully!
Copied Directory [/vendor/roumen/feed/src/views] To [/resources/views/vendor/feed]
Publishing complete for tag []!
Nothing to migrate.
Clearing cache...
PHP Fatal error:  Uncaught ErrorException: count(): Parameter must be an array or an object that implements Countable in /var/www/html/Cachet/vendor/graham-campbell/exceptions/src/ExceptionIdentifier.php:51
Stack trace:
#0 [internal function]: Illuminate\Foundation\Bootstrap\HandleExceptions->handleError(2, 'count(): Parame...', '/var/www/html/C...', 51, Array)
#1 /var/www/html/Cachet/vendor/graham-campbell/exceptions/src/ExceptionIdentifier.php(51): count(NULL)
#2 /var/www/html/Cachet/vendor/graham-campbell/exceptions/src/ExceptionHandlerTrait.php(47): GrahamCampbell\Exceptions\ExceptionIdentifier->identify(Object(ErrorException))
#3 /var/www/html/Cachet/bootstrap/cache/compiled.php(2163): GrahamCampbell\Exceptions\ExceptionHandler->report(Object(ErrorException))
#4 [internal function]: Illuminate\Foundation\Bootstrap\HandleExceptions->handleException(Object(ErrorException))
#5 {main}
  thrown in /var/www/html/Cachet/vendor/graham-campbell/exceptions/src/ExceptionIdentifier.php on line 51
PHP Fatal error:  Uncaught ErrorException: count(): Parameter must be an array or an object that implements Countable in /var/www/html/Cachet/vendor/graham-campbell/exceptions/src/ExceptionIdentifier.php:51
Stack trace:
#0 [internal function]: Illuminate\Foundation\Bootstrap\HandleExceptions->handleError(2, 'count(): Parame...', '/var/www/html/C...', 51, Array)
#1 /var/www/html/Cachet/vendor/graham-campbell/exceptions/src/ExceptionIdentifier.php(51): count(NULL)
#2 /var/www/html/Cachet/vendor/graham-campbell/exceptions/src/ExceptionHandlerTrait.php(47): GrahamCampbell\Exceptions\ExceptionIdentifier->identify(Object(Symfony\Component\Debug\Exception\FatalErrorException))
#3 /var/www/html/Cachet/bootstrap/cache/compiled.php(2163): GrahamCampbell\Exceptions\ExceptionHandler->report(Object(Symfony\Component\Debug\Exception\FatalErrorException))
#4 /var/www/html/Cachet/bootstrap/cache/compiled.php(2181): Illuminate\Foundation\Bootstrap\HandleExceptions->handleException(Object(Symfony\Component\Debug\Exception\FatalErrorException))
 in /var/www/html/Cachet/vendor/graham-campbell/exceptions/src/ExceptionIdentifier.php on line 5

Is this down to a compatibility issue?