So with GNOME 40, almost all applications moved away from unstable odd version numbers and switched to .alpha, .beta, .rc instead. However, most GNOME libraries ignored this switch, as not many libraries were originally following GNOME versioning in the first place (which is fine). Problem is, even/odd versioning is confusing and it’s worst for libraries, where some libraries may follow the practice, some don’t, and for a few it can even be unclear!
My suggestion is to adopt alpha/beta/rc versioning and get rid of odd versions completely. Having multiple numbered alpha releases and multiple numbered beta releases is fine if desired.
The downside of removing even/odd versioning is the third component of your
FOO_CHECK_VERSION macro will no longer be usable for unstable releases, which may be potentially annoying. And you’ll need a couple build system adjustments. But I think the advantage of avoiding unstable version confusion outweighs the cost.
Opinions welcome. Maintainers, nobody is going to force you to adopt a different versioning scheme, but it’s a suggestion to consider.