When you have multiple modules for production and development versions of your app so that both can be installed at once and library projects that depend on library projects that depend on library projects—all of which have different overlapping jar dependencies—you are on your own. Build order - Multi-module builds are a directed, acyclic graph and the order of their compilation can be determined by the build system. Non-Android projects - Modules should not have to be Android library projects to be part of the build path.