The KDE neon 6 extension sets a different build environment for core22 and core24 snaps, but the reference only listed one set of variables. That list was also out of date: `PATH` was missing `$CRAFT_STAGE/usr/bin`, the core24 Mesa library path was missing, `CMAKE_PREFIX_PATH` used `;` separators and pointed to the SDK snaps' roots instead of their `usr` directories, and `CMAKE_FIND_ROOT_PATH` isn't set anymore. The build environment is now shown in core24 and core22 tabs, following the layout of the GNOME extension reference. I generated the values with `KDENeon6.get_part_snippet()` for each base and checked that the documented YAML matches them exactly. The page also said that only the project's main part receives the variables, but the extension adds them to every part, so I corrected that sentence and added a meta description to the page. Fixes #5275 --- - [x] I've followed the [contribution guidelines](https://github.com/canonical/snapcraft/blob/main/CONTRIBUTING.md). - [x] I've signed the [CLA](http://www.ubuntu.com/legal/contributors/). - [x] I've successfully run `make lint && make test`. - [x] I've added or updated any relevant documentation. - [x] In documents I changed, I [added a meta description](https://canonical-starflow.readthedocs-hosted.com/how-to/add-a-page-meta-description/) if one was missing. - [ ] I've updated the relevant release notes.