Apple Safari Security Update (HT212223) won't install: "An error occurred while setting file attributes."

[godzfire]

Mac Mini 2018, Mojave 10.14.6: Running Safari 14.0.3 (14610.4.3.1.6). Trying to install the Safari Security Update (HT212223) [https://support.apple.com/en-us/HT212223] from software update. But it keeps failing out saying "An error occurred while setting file attributes." "An error occurred while installing the selected updates."

In the console here's the error message related to them:
error 2021-04-23 18:11:31.905870 -0500 com.apple.preferences.softwareupdate.remoteservice
Install finished with error: Error Domain=PKInstallErrorDomain Code=119 "An error occurred while setting file attributes." UserInfo={SUErrorUpdateTitle=Safari, NSLocalizedDescription=An error occurred while setting file attributes., NSURL=file:///Library/Updates/071-10830/Safari14.0.3MojaveAuto.pkg, PKInstallPackageIdentifier=com.apple.pkg.Safari14.0.3MojaveAuto, SUErrorRelatedCode=SUErrorCodeInstallFailure, SUErrorUpdateProductKey=071-10830}

error 2021-04-23 18:11:31.907362 -0500 com.apple.preferences.softwareupdate.remoteservice
PrefPane: installDidFinishWithError - 071-10830: Error Domain=SUOSUErrorDomain Code=200 "An error occurred while setting file attributes." UserInfo={NSLocalizedRecoverySuggestion=An error occurred while installing the selected updates., NSLocalizedDescription=An error occurred while setting file attributes., NSUnderlyingError=0x6000021298f0 {Error Domain=PKInstallErrorDomain Code=119 "An error occurred while setting file attributes." UserInfo={SUErrorUpdateTitle=Safari, NSLocalizedDescription=An error occurred while setting file attributes., NSURL=file:///Library/Updates/071-10830/Safari14.0.3MojaveAuto.pkg, PKInstallPackageIdentifier=com.apple.pkg.Safari14.0.3MojaveAuto, SUErrorRelatedCode=SUErrorCodeInstallFailure, SUErrorUpdateProductKey=071-10830}}

 

[godzfire]

For anyone who sees this or has a similar issue, here's some additional info and what I was able to do to fix it:

- Also started happening with the recently pushed March 2021 Security Updates
- Didn't happen on my MacBook Pro which I clone to, the installs went through ok
- Tried creating/logging into a brand new account and install; same error
- Tried booting into Safe Mode and installing per an Apple Community Specialist; same error

Finally, on a whim I decided to check my System Integrity Protection (SIP) status since I always run it off because it's a pain and causes issues: It somehow got enabled.

I turned it back off and tried the updates again, they installed without any issues.