(command.CommandList
  children: [
    (C {<set>} {<-e>})
    (C {<cd>} 
      {
        (command_sub
          left_token: <Id.Left_DollarParen '$('>
          child: 
            (C {<dirname>} 
              {
                (DQ 
                  (braced_var_sub
                    token: <Id.VSub_Name BASH_SOURCE>
                    bracket_op: (bracket_op.ArrayIndex expr:{<Id.Lit_Digits 0>})
                  )
                )
              }
            )
        ) <'/..'>
      }
    )
    (C {<echo>} {(DQ <'*** Patching SDK'>)})
    (C {<dart>} {<-c>} {<'tool/patch_sdk.dart'>} {<'tool/input_sdk'>} {<'gen/patched_sdk'>})
    (C {<echo>} {(DQ <'*** Compiling SDK to JavaScript'>)})
    (command.Simple
      words: [
        {<dart>}
        {<-c>}
        {<'tool/build_sdk.dart'>}
        {<--dart-sdk>}
        {<'gen/patched_sdk'>}
        {<--dart-sdk-summary> <Id.Lit_Equals '='> <build>}
        {<--summary-out>}
        {<'lib/sdk/ddc_sdk.sum'>}
        {<--modules> <Id.Lit_Equals '='> <amd>}
        {<-o>}
        {<'lib/js/amd/dart_sdk.js'>}
        {<--modules> <Id.Lit_Equals '='> <es6>}
        {<-o>}
        {<'lib/js/es6/dart_sdk.js'>}
        {<--modules> <Id.Lit_Equals '='> <common>}
        {<-o>}
        {<'lib/js/common/dart_sdk.js'>}
        {<--modules> <Id.Lit_Equals '='> <legacy>}
        {<-o>}
        {<'lib/js/legacy/dart_sdk.js'>}
        {(DQ ($ Id.VSub_At '$@'))}
      ]
      redirects: [
        (redir
          op: <Id.Redir_Great '>'>
          loc: (redir_loc.Fd fd:1)
          arg: {<'tool/sdk_expected_errors.txt'>}
        )
      ]
      do_fork: T
    )
  ]
)