(command.CommandList
  children: [
    (C {<Id.KW_Set set>} {<-e>})
    (C {<cd>} 
      {
        (DQ 
          (command_sub
            left_token: <Id.Left_DollarParen '$('>
            child: (C {<dirname>} {(DQ ($ Id.VSub_Number '$0'))})
          ) <'/..'>
        )
      }
    )
    (C {<'script/update'>})
    (command.AndOr
      ops: [Id.Op_DAmp]
      children: [
        (C {<test>} {<-z>} {(DQ ($ Id.VSub_DollarName '$RACK_ENV'))})
        (command.ShAssignment
          pairs: [
            (assign_pair
              lhs: (sh_lhs_expr.Name name:RACK_ENV)
              op: assign_op.Equal
              rhs: {(SQ <development>)}
              spids: [47]
            )
          ]
        )
      ]
    )
    (C {<foreman>} {<start>} {<-p>} {<9393>})
  ]
)