It isn't difficult, but it is friction. You hit compile and a few seconds later you get an error that is unrelated to the change you wanted to test. I agree with all those errors once those changes are for production, but sometimes I wish the compiler would just shut up and let me test the actual change I just made to ensure it works.

Commenting out a few variables isn't always easy either. Every try to add const to a legacy C++ project - it can take days to fix all the errors resulting from adding const to something that clearly is const in usage. I don't know zig, but I wouldn't be surprised if sometimes you get into this type of situation in a large code base (does anyone have a very large code base in zig yet?)