Recent software systems usually feature an automated failure reporting component, with which a huge number of failures are collected from software end-users. With a proper support of failure indexing, which identifie s failure s due to the same fault, the collected failure data can help developers prioritize failure diagnosis, among other utilities of the failure data. Since crashing failure s can be effectively indexed by program crashing venues, current practice has seen great success in prioritizing crashing failures. A recent study of bug characteristics indicates that as excellent memory checking tools are widely adopted, semantic bugs and the resulting noncrushing failure s have become dominant. Unfortunately, the problem of how to index noncrashing failures has not been seriously studied before. In previous study, two techniques have been proposed to index noncrushing failures, and they are T-PROXIMITY and R-PROXIMITY. However, as T-PROXIMITY indexes failures by the profile of the entire execution, it is generally not effective because most information in the profile is faultirrelevant. On the other hand, although R-PROXIMITY is more effective than T-PROXIMITY, it relies on a sufficient number of correct executions that may not be available in practice. In this paper, we propose a dynamic slicing-based approach, which does not require any correct executions, and is comparably effective as R-PROXIMITY. A detailed case study with gzip is reported, which clearly demonstrates the advantages of the proposed approach.