Cargo does the de-duplication, but only up to a point. If two packages request the same dependency with semver ranges that have a common overlap (say, `1.4` and

Cargo does the de-duplication, but only up to a point. If two packages request the same dependency with semver ranges that have a common overlap (say, `1.4` and `1.6`) then it will use a single package for both (say, `1.7.12`). But if they request semver-incompatible versions (`2.1` and `1.6`) then cargo will use both.