Throwing an SSR error for svelte third-party packages with npm protocol

Describe the bug

When hot reloading and initially spinning up pnpm run dev an error that causes a 500 message to be displayed to the client is seen when attempting to import a .svelte component from a node_module.

Reproduction

dextermb/bug-hero-icons-svelte-kit

Steps to reproduce:

• pnpm init svelte@next app
• pnpm i -D svelte-heroicons@npm:svelte-hero-icons
• Import icon into page
• pnpm run dev

Logs

18:29:23 [vite] Error when evaluating SSR module /src/routes/index.svelte:
TypeError [ERR_UNKNOWN_FILE_EXTENSION]: Unknown file extension ".svelte" for /Users/dexter/projects/svelte/hero-icons-svelte-kit/node_modules/.pnpm/svelte-hero-icons@4.0.3/node_modules/svelte-hero-icons/Icon.svelte
    at Loader.defaultGetFormat [as _getFormat] (internal/modules/esm/get_format.js:71:15)
    at Loader.getFormat (internal/modules/esm/loader.js:102:42)
    at Loader.getModuleJob (internal/modules/esm/loader.js:231:31)
    at async ModuleWrap.<anonymous> (internal/modules/esm/module_job.js:58:21)
    at async Promise.all (index 230)
    at async link (internal/modules/esm/module_job.js:63:9)

System Info

npx: installed 1 in 1.125s

  System:
    OS: macOS 12.2.1
    CPU: (8) x64 Intel(R) Core(TM) i5-1038NG7 CPU @ 2.00GHz
    Memory: 50.17 MB / 16.00 GB
    Shell: 5.8 - /bin/zsh
  Binaries:
    Node: 14.16.0 - ~/.nvm/versions/node/v14.16.0/bin/node
    Yarn: 1.22.10 - ~/.nvm/versions/node/v14.16.0/bin/yarn
    npm: 6.14.11 - ~/.nvm/versions/node/v14.16.0/bin/npm
  Browsers:
    Brave Browser: 97.1.34.81
    Chrome: 99.0.4844.51
    Firefox: 94.0.1
    Safari: 15.3
  npmPackages:
    @sveltejs/adapter-auto: next => 1.0.0-next.30 
    @sveltejs/kit: next => 1.0.0-next.292 
    svelte: ^3.44.0 => 3.46.4 

Severity

serious, but I can work around it

Additional Information

Seems to work fine in @sveltejs/kit:1.0.0-next.285 but not 1.0.0-next.292.

Edit: After further investigation it seems like it could be down to aliased modules.