Upgrade tool fails with unactionable error message

[charlieforward9]

What version of Tailwind CSS are you using?

v3.4.0

What build tool (or framework if it abstracts the build tool) are you using?

npx @tailwindcss/upgrade

What version of Node.js are you using?

v22.14.0

What browser are you using?

N/A

What operating system are you using?

macOS

Reproduction

Running npx @tailwindcss/upgrade

≈ tailwindcss v4.0.14

│ Searching for CSS files in the current directory and its subdirectories… 

│ ↳ Linked `./tailwind.config.cjs` to `./src/styles.css` 

│ Migrating JavaScript configuration files… 

│ ↳ Could not load the configuration file: Cannot use 'in' operator to search for 
│   '__isOptionsFunction' in tailwindcss 

My config file:

/**
 * Configuration file for Tailwind CSS.
 * This file defines the configuration for Tailwind CSS.
 * The content property specifies which files to include in the CSS generation process.
 * The theme property extends the default theme configuration.
 * The plugins property specifies the plugins to use.
 * For more information on how to customize Tailwind, visit the official documentation:
 * {@link https://tailwindcss.com/docs}
 * @type {import('tailwindcss').Config} */

// eslint-disable-next-line no-undef
module.exports = {
  content: {
    relative: true,
    files: [
      "src/core/Agroview.tsx",
      "src/core/bars/*.tsx",
      "src/core/components/*.tsx",
      "src/**/**/**/*.tsx",
    ],
  },
  theme: {
    extend: {
      backgroundImage: {
        "loading-logo": "url('../assets/images/Agroview_FullLogo.svg')",
      },
      height: {
        nav: "7vh",
        op: "93vh",
      },
      minHeight: {
        op: "93vh",
      },
      maxHeight: {
        "60vh": "60vh",
        "80vh": "80vh",
        "90vh": "90vh",
        33: "24rem",
        op: "93vh",
      },
      minWidth: {
        96: "24rem",
      },
      width: {
        expand: "70rem",
      },
      zIndex: {
        popup: 2,
        control: 10,
        nav: 1000,
        modal: 1100,
      },
      screens: {},
      colors: {
        agroGreen: "#239446",
        agroOrange: "#F36F21",
        customGrayBorder: "#eeeeee",
      },
      fontFamily: {
        sans: ["Inter", "sans-serif"],
      },
    },
  },
  plugins: ["tailwindcss", "autoprefixer"],
};

I am not clear if this config file is crashing the program, or if another file is what is causing the problem, please help me understand what __isOptionsFunction is supposed to be doing to narrow down the reproduction of this issue.

[wongjn]

Your v3 configuration is invalid, the plugins array should be an array of Tailwind plugins, not strings. Since they wouldn't do anything, I would expect you can simply remove it:

     },
   },
-  plugins: ["tailwindcss", "autoprefixer"],
 };

[nebula0225]

Donwngrade node version to 20