Comment by kibwen

> If version 0.7 turned out to hit the right API and not require backward incompatible changes, releasing a version 1.0 would be as disruptive as a major version change

Nope, this is what the semver trick is for: https://github.com/dtolnay/semver-trick

TL;DR: You take the 0.7 library, release it as 1.0, then make a 0.7.1 release that does nothing other than depend on 1.0 and re-export all its items. Tada, a compatible 1.0 release that 0.7 users will get automatically when they upgrade.

Even more interesting is that you can use this to coordinate only partially-breaking changes, e.g. if you have 100 APIs in your library but only make a breaking change to one, you can re-export the 99 unbroken APIs and only end up making breaking changes in practice for users who actually use the one API with breaking changes.