Both after updating from macOS Mojave 10.14.6 to macOS Catalina 10.15.5 and again when updating from 10.15.5 to 10.15.6, the installation failed with
OSStatus error -37. This failure leaves the computer in an endless update loop where it tries to perform the software installation, fails, reboots, and tries again. Forcing the computer to boot from the main internal drive fails: the computer is no longer bootable.
A clean install does work successfully. But, installing macOS Catalina (or a Catalina update) in-place fails.
How can I resolve the installation failure without wiping my computer clean and reinstalling from scratch?