Porting Linux device drivers to target more recent and older Linux kernel versions to compensate for the ever-changing kernel interface is a continual problem for Linux device driver developers. Acquiring information about interface changes is a necessary, but tedious and error prone, part of this task. In this paper, we propose two tools, Prequel and gcc-reduce, to help the developer collect the needed information. Prequel provides language support for querying git commit histories, while gcc-reduce translates error messages produced by compiling a driver with a target kernel into appropriate Pre-quel queries. We have used our approach in porting 33 device driver files over up to 3 years of Linux kernel history , amounting to hundreds of thousands of commits. In these experiments, for 3/4 of the porting issues, our approach highlighted commits that enabled solving the porting task. For many porting issues, our approach retrieves relevant commits in 30 seconds or less.