In the case of make, with missing dependencies, it can result in a file not being re-compiled when it should be. If you are compiling C, this can result in the definition of a function definition being different in two different compilation units. When one of those compilation units calls a function defined in the other, your program's behavior breaks. All due to a change in the build tool.
That's true. I qualified my statement with probably because there are exceptions. Protecting against those sorts of errors is why my release candidates are done with a clean build and newly fixed bugs are reverified on that package before release.
