For some reason, Rollup refuses to recognize my global external dependencies.

From my vite.config.ts:

export default defineConfig({
  build: {
    rollupOptions: {
      external: ['radash', '@leeoniya/ufuzzy'],
      output: {
        globals: {
          radash: '_',
          '@leeoniya/ufuzzy': 'Fuzzy',
        },
      },
    },
  },
[...]

From my Vite build:

No name was provided for external module "radash" in "output.globals" – guessing "_".
No name was provided for external module "@leeoniya/ufuzzy" in "output.globals" – guessing "Fuzzy".
No name was provided for external module "radash" in "output.globals" – guessing "_".
No name was provided for external module "@leeoniya/ufuzzy" in "output.globals" – guessing "Fuzzy".
No name was provided for external module "radash" in "output.globals" – guessing "_".
No name was provided for external module "@leeoniya/ufuzzy" in "output.globals" – guessing "Fuzzy".
No name was provided for external module "radash" in "output.globals" – guessing "_".
No name was provided for external module "@leeoniya/ufuzzy" in "output.globals" – guessing "Fuzzy".
No name was provided for external module "radash" in "output.globals" – guessing "_".
No name was provided for external module "@leeoniya/ufuzzy" in "output.globals" – guessing "Fuzzy".
No name was provided for external module "radash" in "output.globals" – guessing "_".
No name was provided for external module "@leeoniya/ufuzzy" in "output.globals" – guessing "Fuzzy".

I’ve also tried using vite-plugin-externals with the same result. The consequences is that my builds, which finish successfully, are broken when loaded in the browser and throw a console error:

Failed to resolve module specifier "radash". Relative references must start with either "/", "./", or "../".

Is this a bug or am I doing something wrong? I’m using Sveltekit if that matters.