Attached, a patch to improve valac version detection. The vala compiler, valac, can report the API version it supports. For releases, this is the same as the major & minor version of the compiler, so for example:
$ valac --version
$ valac --api-version
The advantage of using the API version is that it's semantically meaningful. It's also simpler to parse! It can be to allow a 3rd-party, patched, or unreleased compiler to be used more easily.
(For example, the current Vala git master compiler reports:
$ valac-0.52 --version
$ valac-0.52 --api-version