[burntsushi]

That doesn't make sense. The most it could be is 3: regex 0.1.x, regex 0.2.y and regex 1.a.b. You can't have more because Cargo unifies on semver compatible versions and regex only has 3 semver incompatible releases. Plus, regex 1.0 has been out for eons. Pretty much everyone has moved off of 0.1 and 0.2.

[spoiler]

The reason he went down this rabbit hole was because he was chronically running low on disk space, and his target dir was one of the largest contributors.

Not sure how he actually got the number; this was just a frustrated Slack message like 4 years ago

A sibling comment mentions we could have been using Cargo workspaces wrong... So, maybe?

[burntsushi]

He probably just needed to run `cargo clean` occasionally.

But you definitely aren't finding hundreds of versions of `regex` in the same dependency tree.