### Bug Description When building a snap using at least revision 12523 to build snaps which built successfully with revisions like 12503 (latest/edge versus 8.x/edge), snapcraft will now emit some error messages. ### To Reproduce Install snapcraft from latest/edge, build the snap with `snapcraft`. ### Environment Ubuntu 23.10, building with `snapcraft --use-lxd`. ### snapcraft.yaml ```yaml name: my-snap-name # you probably want to 'snapcraft register <name>' base: core24 # the base snap is the execution environment for this snap version: '0.1' # just for humans, typically '1.2+git' or '1.3.2' summary: Single-line elevator pitch for your amazing snap # 79 char long summary description: | This is my-snap's description. You have a paragraph or two to tell the most important story about your snap. Keep it under 100 words though, we live in tweetspace and your description wants to look good in the snap store. grade: devel # must be 'stable' to release into candidate/stable channels confinement: devmode # use 'strict' once you have the right plugs and slots parts: my-part: # See 'snapcraft plugins' plugin: nil apps: my-app: command: bash environment: foo: 1 ``` ### Relevant log output ```shell dilyn@Ares:~/test -> snapcraft Starting snapcraft, version 8.3.2.post71+git3508cf39 Logging execution to '/home/dilyn/.local/state/snapcraft/log/snapcraft-20240905-191836.634265.log' Bad snapcraft.yaml content: - input should be a valid string (in field 'apps.my-app.environment.foo') ``` ### Additional context Quoting `1` results in successful builds (sans an error message unrelated to this issue).