(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/bootstrap'>})
    (C {<echo>} {(DQ <'==> Updating db…'>)})
    (C {<'bin/rake'>} {<db> <Id.Lit_Colon ':'> <migrate>})
  ]
)