The core task of a system for updating software – with the notable exception of macOS and firmware – is straightforward. It needs to detect which version you’re running, check whether there’s a more recent version available which is compatible with the version of macOS running, download any update, and install it. Yet this often seems to go wrong somewhere along the line. We may get updates pushed at our Macs (such as Apple’s security data updates), made available for us to pull down, or offered when we feel like downloading and installing them. One thing’s for sure: they won’t always happen as they should.
Starting with the most essential, Apple’s security data updates should be pushed to each Mac when it’s running, soon after their release. If you’re lucky, it will download and install within an hour or so of being made available, but sometimes an update doesn’t arrive for another day or two. This is one of the reasons why my utilities SilentKnight and LockRattler have become so popular, as they let you check to see if an update is available and force it to be downloaded and installed. They don’t use any trickery to do that, just standard commands you could enter into Terminal yourself if you preferred.
There are many different systems used for ‘pulled’ updates which you request or approve. That’s because Apple has never built in a standard mechanism for handling this in macOS: that used in its Software Update pane is private, and third party vendors can’t use it for their own products. So everyone else has had to come up with their own system.
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