Compile-time configurable system software requires a thorough design and im-plementation of the resulting variability. The Linux kernel constitutes a prominent example of such system software; Linux v3.12 ships over 12 000 configurable features with dozens of supported hardware architectures. Previous research shows that the Linux kernel suffers from hundreds of variability related defects. In this thesis, I shall present an empirical case study of variability defects in 24 versions of the Linux kernel, and present a tool that checks GIT commits for such bugs in order to avoid the introduction to the source code. i Kurzfassung Konfigurierbare System Software erfordert einen modularen Softwareentwurf, der in vielen Fällen durch die Instrumen...