In the same source you sent:
Example: 1.0.0-alpha < 1.0.0-alpha.1 < 1.0.0-alpha.beta < 1.0.0-beta < 1.0.0-beta.2 < 1.0.0-beta.11 < 1.0.0-rc.1 < 1.0.0
RC comes before the stable release
You can't have 1.0.0 then release 1.0.0-rc.1
The latest release of hived is 1.27.7rc16 (https://gitlab.syncad.com/hive/hive/-/tags) and you can't release that after releasing 1.27.7
RC: Release Candidate
1.27.7rc16 means it is a candidate to become 1.27.7
And no. hived does not follow semver.
I see, apparently developers made a mistake with tagging
1.27.7, and they did not correct it by properly incrementing minor release number... Indeed it is a violation of versioning best practice. (I reported this issue as https://gitlab.syncad.com/hive/hive/-/issues/740)At least versioning pattern seems to suggest that there could have been an intent to use semver...
Regarding "Ubuntu 22 is the recommended OS for Hive apps", host OS does not matter if you run Docker container anyway. Recommendation is obviously misguided, but at least it have some validity as notion that application builds from source in that environment (and that Ubuntu 22 is used as development environment by some active developers).