Why we can’t repair system permissions, and some pitfalls and promise in the new technique of repairing permissions on the Home folder.
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Apple has started recommending users to repair permissions – not generally, but in the Home folder. Here’s my experience, and a tool to make this easier.
We stopped repairing permissions, because of SIP. Now Apple recommends it for a wide range of problems – only this repairs them on your Home folder.
The Eclectic Light Company 