How to Pet a Two-Headed Snake? Solving Cross-Repository Compatibility Issues with Hera

Many programming languages and operating system communities maintain software repositories to build their own ecosystems. The repositories often provide management tools to help users using the packages. The tools are often, if not all the times, well-designed to handle intra-repository dependencies without considering inter-repository dependencies. The users, however, often need packages from different repositories, and thus may suffer from compatibility issues. We refer to these issues as Cross-repository Compatibility (CC) issues. Existing works typically focus on a single software repository and are insufficient to detect CC issues.