Automation shell override causes invalid options.shell property

My settings.json includes the following:

    "terminal.integrated.automationProfile.windows": {
      "path": "${env:windir}\\System32\\cmd.exe",
      "args": [],
      "icon": "terminal-cmd"
    },

I admit I'm pretty confused about whether this option is supposed to be a string (a key of terminal.integrated.profiles.windows) or an object, but the TypeScript types suggest it's supposed to be an object. In this state, the Makefile extension says this:

TypeError [ERR_INVALID_ARG_TYPE]: The "options.shell" property must be one of type boolean or string. Received an instance of Object
Preprocessing: "undefined"
Configure failed.
Configure elapsed time: 0.388
Dryrun timeout. Verify that the make command works properly in your development terminal (it could wait for stdin).

(No dryrun.log was generated.)