Yet another error is that if you remove one scss file, the old generated css file will not be removed after a rebuild. If the next build step does something like wildcard-include all *.css-files you will get problems.
Blind includes are a dumb to do (it's one easy way to exploit a source codebase). The better way is to generate your include from, you know, the actual way your codebase is. Use `$(OUT)` to build your include statement. That var says, "load any of my files", not the lazy/dangerous form of, "load any files that might actually be there".
And yes, by that logic, `SRC = $(shell ls scss/*.scss)` is dumb. That is not lost upon me.
