Error on NextJS build

[ismi-abbas]

Using

export const fontSans = FontSans({
  subsets: ['latin'],
  variable: '--font-sans',
})

on the root layout will throw type error during build

Type error: Type 'OmitWithTag<typeof import("C:/Users/test/projects/nextjs-event-manager/app/layout"), "metadata" | "default" | "config" | "generateStaticParams" | "revalidate" | "dynamic" | "dynamicParams" | ... 6 more ... | "generateViewport", "">' does not satisfy the constraint '{ [x: string]: never; }'.
  Property 'fontSans' is incompatible with index signature.
    Type 'NextFontWithVariable' is not assignable to type 'never'.

   6 |
   7 | // Check that the entry is a valid entry
>  8 | checkFields<Diff<{
     |             ^
   9 |   default: Function
  10 |   config?: {}
  11 |   generateStaticParams?: Function

Removing export will make it success

Temporary fix

const fontSans = FontSans({
  subsets: ['latin'],
  variable: '--font-sans',
})

Refer NextFont gives a type error on Build mode

[shadcn]

@ismi-abbas Where are you placing the font export? Which file?

[ismi-abbas]

@ismi-abbas Where are you placing the font export? Which file?

At the app/layout.tsx. I've initiated the ui with src folder, then I remove it, configured all the path to be correct, but still encounter problem.

{
  "$schema": "https://ui.shadcn.com/schema.json",
  "style": "new-york",
  "rsc": true,
  "tsx": true,
  "tailwind": {
    "config": "tailwind.config.ts",
    "css": "app/globals.css",
    "baseColor": "zinc",
    "cssVariables": true,
    "prefix": ""
  },
  "aliases": {
    "components": "@/components",
    "utils": "@/lib/utils"
  }
}

[shadcn]

Yeah you can't export from the layout.tsx file. I usually keep a lib/fonts.ts file where I keep all font exports.

[emre-turan]

I found myself in the same situation, but I believe we should be more cautious when copying and pasting. However, there is room for improvement in the instructions provided here.