On Tue, 2025-06-10 at 10:05 -0700, Felix Lechner via Users list for the GNU implementation of make wrote: > .DELETE_ON_ERROR
This is invalid makefile syntax: .DELETE_ON_ERROR is a _target_ so you have to add a ":" after it. Make doesn't know what kind of line you are typing until it finds the "separator" character, like ":" versus "=" for example. "Missing separator" means that it didn't find one.