Added patch for 8.x-3.0-alpha7.
The patch #2 looks good but does not account for the processing of attached display arguments, so it needs improvement.
In the latest version of this module config in settings.php should look like this:
$settings['content_sync']['sync'] = '../content/sync';
Works well.
Attached patch file.
+
#36 💬 On 8.3.14 (but not 8.3.13): ERROR: Referenced sniff "SlevomatCodingStandard.ControlStructures.RequireNullCoalesceOperator" does not exist Active works for me.
Also after downgrading Coder to the 8.3.13 version you can upgrade it again to the latest one and Slevomat coding standards appear in phpcs -i. At least it did a "trick" for me.