Software update is stuck on checking for updates on mac

I'm not sure how running software update in the terminal as you describe would make any difference, but based on reported experiences, a few things seem to have helped, even if inconsistently or temporarily. Maybe that's one of them. After months of not having Software Update work, I had it work briefly and I don't know how. I had changed an automatic update setting but I don't believe I saw an immediate affect. Regardless, I finally updated Catalina and later it went back to not working. I revisited here and at some point, I tried booting in safe mode to no avail. Maybe, the only two or three people that reported this problem with Big Sur (here in this thread and in one at mac_forums.com) found success using safe mode (recovery) although one them used it to reinstall the OS. Everyone else that gave their OS (not many) said it was Catalina, and far as I can see, a flurry of similar reports are starting in 2022. That seems interesting if true. The natural reason for Software Update spinning forever is a network problem or just the Apple server itself being unreachable. Some of the people clearly encountered network problems and were able to figure that out. For the rest of us, perhaps the majority, I believe our problem or solution remains unclear. I think the May 16 Catalina update possibly helped me, and deleting the crl cache (after copying it, as described) and restarting appears to work for me. Leaving a hung Software Update running and restarting my iMac (with Software Update being reopened on restart) has been working for me. Other weirdities are that even the Catalina security updates that I was able to download through direct links would not install (infinitely spun just like Software Update) and Howard Oakley's Silent Night would likewise spin forever when attempting to check for security updates. Given the limited number of contributors to this dicussion, and the inconsistencies, I'm not overly certain of much except that Apple is at least at fault in not detecting some error and reporting it to the victim.

It is always risky to follow blindly answers who don't analyze the core of a problem

and just suggests:

1. try this
2. try that
3. …

This is always a risk of damage for the blind follower.

And the lesson of this bug analysis is that all of these risky pieces of advice

would have been avoided if Software Update gave an intelligent error message

upon reading a corrupted certificates database.

To bet users are stupid and can't read error messages is causing a huge damage in the whole IT field.

It is a damage to trust.

I’m not sure about all that, all I know is that command when run on a machine where all you are getting is the endless “checking for updates” symptoms, results in a successful check and any available updates can be selected for install.

Maybe someone smarter than me can explain why that is the case ;)

I tried a few other recommendations like deleting the com.apple.SoftwareUpdate.plist but that didn't work.

This DID!

Thank you!!

Which version of Catalina Security Update are you trying to install?

Its name should look like

Security Update 2022 xxx