{ "defaults":
  { "type": "configure"
  , "target": "defaults (unconfigured)"
  , "arguments_config": ["TOOLCHAIN_CONFIG"]
  , "config":
    { "type": "let*"
    , "bindings":
      [ [ "shell toolchain"
        , { "type": "lookup"
          , "map":
            { "type": "var"
            , "name": "TOOLCHAIN_CONFIG"
            , "default": {"type": "empty_map"}
            }
          , "key": "shell"
          , "default": {"type": "empty_map"}
          }
        ]
      , [ "sh"
        , { "type": "lookup"
          , "map": {"type": "var", "name": "shell toolchain"}
          , "key": "sh"
          , "default": "/bin/sh"
          }
        ]
      , [ "PATH"
        , { "type": "lookup"
          , "map": {"type": "var", "name": "shell toolchain"}
          , "key": "PATH"
          , "default": []
          }
        ]
      ]
    , "body": {"type": "env", "vars": ["sh", "PATH"]}
    }
  }
, "defaults (unconfigured)":
  { "type": "defaults"
  , "arguments_config": ["sh", "PATH"]
  , "sh": [{"type": "var", "name": "sh"}]
  , "PATH": {"type": "var", "name": "PATH"}
  }
}