As far as I can tell it seems to be getting the wrong node version from somewhere.
Debug Information:
OS: Microsoft Windows 10 Home, v10.0.19041
Node Version: v12.20.0
Ghost-CLI Version: 1.15.2
Environment: development
Command: ‘ghost install local’
Message: spawn yarn ENOENT
Exit code: ENOENT
--------------- stdout ---------------
yarn install v1.22.10
[1/5] Validating package.json…
info Visit yarn install | Yarn for documentation about this command.
--------------- stderr ---------------
error ghost@3.38.3: The engine “node” is incompatible with this module. Expected version “^10.13.0 || ^12.10.0 || ^14.15.0”. Got “12.0.0”
warning ghost@3.38.3: The engine “cli” appears to be invalid.
error Found incompatible module.