- [x] Have you followed the [guidelines for contributing](https://github.com/snapcore/snapcraft/blob/master/CONTRIBUTING.md)? - [x] Have you signed the [CLA](http://www.ubuntu.com/legal/contributors/)? - [x] If this is a bugfix. Have you checked that there is a bug report open for the issue you are trying to fix on [bug reports](https://bugs.launchpad.net/snapcraft)? - [x] If this is a new feature. Have you discussed the design on the [forum](https://forum.snapcraft.io)? - [x] Have you successfully run `./runtests.sh static`? - [x] Have you successfully run `./runtests.sh unit`? ----- The build state tracks `build-attributes` as a build property, which means if it changes, the build step is considered dirty. However, a few plugins have also added `build-attributes` to their build properties, which is redundant. This PR makes sure the core Snapcraft properties are handled in the state classes, and keep the plugins handling their own schema. While we have tests covering this, you can verify `build-attributes` still makes the `build` step dirty manually with the following: ``` $ snapcraft init Created snap/snapcraft.yaml. Edit the file to your liking or run `snapcraft` to get started $ snapcraft build Preparing to pull my-part Pulling my-part Preparing to build my-part Building my-part $ echo " build-attributes: [debug]" >> snap/snapcraft.yaml $ snapcraft build Skipping pull my-part (already ran) The 'build' step of 'my-part' is out of date: The 'build-attributes' part property appears to have changed. In order to continue, please clean that part's 'build' step by running: snapcraft clean my-part -s build ```