[xt00]

Gradle is a very strange build system.. it actively downloads things if you are missing things, but then still will only work if you have the right combination of things on your system (on linux at least), and fails in cryptic ways. Not sure I know anybody actively likes Gradle and that entire build system -- there was something previously like ant something, etc.. if you have an older project good luck having it actually build even when trying to use Android Studio.. it seems to only work if you actively use Android Studio quite often and slowly adapt to each random change to keep your project working properly.