Where do the macOS updates and upgrades get saved? My Big Sur upgrade had just about finished before the Server troubles, but errored out, perhaps due to the server issue. Now, server issue resolved, but error as soon as I try to download.

Where do the macOS updates and upgrades get saved?

My Big Sur upgrade (from Catalina 10.15.7) had just about finished before the Server troubles, but errored out—"An error occurred while installing the selected updates."—perhaps due to the server issue.

However, the same error had occurred three previous times, so I didn’t think that much about it.

Now, however, though the server issue is now resolved, according to the System Status webpage, I continue to get the error as soon as I try to download. (Much the same as many others were getting while the macOS Software Update system was having trouble.)

At least in case this doesn’t clear up on its own, I would like to be able to remove the Big Sur install package, to get the upgrade to re-download.

Incidentally, I tried to reboot into Safe Mode, but that appears to be impossible with a wireless keyboard. (My last wired keyboard doesn’t seem to communicate, anymore. The wire is failing. It’s too bad that Apple’s wireless keyboard [the “Space Grey” one with the numeric keypad] doesn’t work as a wired keyboard when plugged in. That would solve it.)