No idea what the “adapter” property does, but it seems like this snippet could use updating in snapcraft.json given much newer snapd:
"adapter": {
"$comment": "Full should be the default, but it requires command-chain which isn't available in snapd until 2.36, which isn't yet stable. Until 2.36 is generally available, continue with legacy as the default.",
"type": "string",
"description": "What kind of wrapper to generate for the given command",
"enum": [
"none",
"legacy",
"full"
],
"default": "legacy"
},