> Many hours of searching for how Gradle detects changes were fruitless, because it doesn't even try, really. Gradle basically always runs everything, which is why it's so goddamn slow. This is because the entire dependency graph is constructed dynamically on every run,

Something that is not clear from the Gradle documentation is that every task must have its input and output defined (inputFile, inputDirectory, outputFile, outputDitectory property). It is absolutely essential so Gradle can infer which task has to be rerun when, for instance, a build is run. This is usually done for the ‘basic’ task (like build, test etc..) but you have to specify it when you have custom task. This can really make a difference in speed. Another trick is to use the console option (gradle build —console plain) so you will see each task that have been run and their status (if they have be runned, or if they have been skipped due to dependencies)