Expand bug-introducing-commit candidate set beyond files modified by the fix

Determine a cost-effective method to expand the Simple-SZZ-Agent commit candidate set beyond only the files modified by the fix commit, so that bug-introducing commits introduced in other files can be identified without incurring prohibitive infrastructure costs.

Background

Simple-SZZ-Agent forms its candidate set by aggregating the commit histories of files modified by the fix commit. The authors’ error analysis on DS_LINUX-26 shows that some failures occur because the true bug-introducing commit resides in a different file and is therefore absent from the candidate set.

Expanding the candidate pool to include commits outside the modified files would address this limitation, but naive expansion risks excessive resource usage. The paper highlights the need for an approach that broadens coverage while remaining practical in terms of infrastructure and cost.