No, it's explicitly not. Semver says:
reply> Major version zero (0.y.z) is for initial development. Anything MAY change at any time. The public API SHOULD NOT be considered stable.
Cargo is explicitly breaking with Semver by considering 0.3.5 compatible with 0.3.6.
To go further, semver provides semantics and an ordering but it says nothing about version requirement syntax. The caret operator to describe a range of versions is not part of the spec. It was introduced by initial semver-aware package managers such as npm or gem. Cargo decided to default to the caret operator, but it's still the caret operator.
replyIn practice, there's no real issue with using the first non-zero component to define the group of API-compatible releases and most package managers agree on the semantics.
Thank you.
replyEventually this will get cleared up. I’m close than I’ve ever been to actually handling this, but it’s been 9 years already, so what’s another few months…