Cache is always out of date

[aryzing]

Recently upgraded to v3.0.11, and I simply can't run my project anymore. Whenver I run snowpack in dev mode, as soon as I open the app on the browser, snowpack warns about the cache being out of date and starts building.

Not sure why snowpack thinks its cache is out of date. There are no modifications made to the files prior to opening the browser. Simply running snowpack, clicking on the link displayed on the terminal once the build finishes, and as soon as the app loads, snowpack declares the cache to be out of date and starts rebuilding.

Any help appreciated, completely blocked by this.

~/workspace/anccre-2-client (develop)$ yarn dev
yarn run v1.22.5
$ snowpack dev
  http://localhost:8080 • http://192.168.0.104:8080
  Server started in 20ms.


[snowpack] Dependency cache out of date. Updating...
[snowpack] ! building dependencies...

As a side question, how does snowpack determine its cache is out of date?

snowpack.config.js

// Snowpack Configuration File
// See all supported options: https://www.snowpack.dev/#configuration

/** @type {import("snowpack").SnowpackUserConfig } */
module.exports = {
  mount: {
    src: "/dist",
    public: "/",
  },
  plugins: [
    "@snowpack/plugin-react-refresh",

    // Needed to support new React transform.
    // See https://github.com/snowpackjs/snowpack/discussions/1469#discussioncomment-118237
    "@snowpack/plugin-babel",
    "@snowpack/plugin-dotenv",
  ],
  // installOptions: {},
  devOptions: {
    open: "none",
    output: "stream",
  },
  // buildOptions: {},
  packageOptions: {
    knownEntrypoints: [
      "@emotion/styled/base",
      "react/jsx-runtime",
    ],
  },
};

[aryzing]

Found the issue. Turns out one of the libs being used, remark-frontmatter, has no main field in its package.json.

After manually adding a main field pointing to the only file in the package, index.js, snowpack behaves as expected.

Q's:

• How come snowpack doesn't pick up on index.js by default?
• How hard would it be to add support for packages with none of the expected entry fields in package.json (main, module, etc)?
• Would it be worth adding a warning or error message when such a package is encountered?

[aryzing]

Thanks for the tip. That is quite surprising given I can consistently replicate the failure: whenever "main": "index.js", is added, snowpack works as expected. When removed, it fails as soon as the app is loaded and continues to invalidate the cache and rebuild deps.

An additional clue I can provide is that with "main": "index.js",

• the snowpack cache (node_modules/.cache/snowpack/development) contains a remark-frontmatter.js file
• emitted files have import statements such as import frontmatter from "../../../_snowpack/pkg/remark-frontmatter.js";

Without "main": "index.js",

• the cache does not contain the frontmatter module
• the import statements look like import frontmatter from "remark-frontmatter";
• receive the following message in the console,

[snowpack] Error: Import "remark-frontmatter" could not be resolved.
If this import doesn't exist in the source file, add "knownEntrypoints": ["remark-frontmatter"] to your Snowpack config "packageOptions".

Does this help?

[ChristianMurphy]

Have you tried the recommendation from the log?

add "knownEntrypoints": ["remark-frontmatter"] to your Snowpack config "packageOptions".

[ChristianMurphy]

Also have you tried clearing the node_modules folder, then doing a clean reinstall of packages?

[aryzing]

Yes, should have mentioned, did try theknownEntrypoints suggestion and, just now, a fresh node_modules install.

Was surprised to see the suggestion given it does appear as an import in the code.

[ChristianMurphy]

Sounds like a bug to me, but perhaps a core maintainer could weigh in.