(CommandList
  children: [
    (C {(set)} {(-e)})
    (C {(cd)} 
      {
        (DQ 
          (CommandSubPart
            command_list: (CommandList children:[(C {(dirname)} {(DQ ($ VSub_Number '$0'))})])
            left_token: <Left_CommandSub '$('>
            spids: [19 25]
          ) (/..)
        )
      }
    )
    (C {(script/update)})
    (AndOr
      children: [
        (C {(test)} {(-z)} {(DQ ($ VSub_Name '$RACK_ENV'))})
        (Assignment
          keyword: Assign_None
          pairs: [
            (assign_pair
              lhs: (LhsName name:RACK_ENV)
              op: Equal
              rhs: {(SQ <development>)}
              spids: [47]
            )
          ]
          spids: [47]
        )
      ]
      op_id: Op_DAmp
    )
    (C {(foreman)} {(start)} {(-p)} {(9393)})
  ]
)