A dev who ships open-source tools asked how breakpoint handles vendored code. I ran it on pip to answer him — and the answer was embarrassing: pip vendors its deps under _vendor, my exclusion only listed vendor, so the top 8 rows were all vendored files. His question found a hole before he ran a line.
v15 strips naming wrappers from dir names before matching. pip top 8 now all real source. django, pydantic, kotlinx-datetime unchanged.