Today, business process designers can choose from an increasing number of analysis tools to check their process model with respect to defects or flaws, before, e.g., deploying the model in a process engine. Answering questions about the tools' effectiveness though is difficult, as their validation often lacks empirical evidence. In particular, for a modeling language like BPMN, where the process is the product, tools are validated by means of case studies or even artificial process examples. We here advocate instead an approach to systematically mine software repositories on GitHub.com for a large corpus of BPMN business process models and discuss how it can be used for tool validation and guiding tool development, using the example of the linting tool BPMNspector.