Webpack 4.19.1: undefinedresolvePathname is not defined (but 4.19.0 works!)

[sorenhoyer]

Bug report

What is the current behavior?

The first time we npx start our project after a fresh npm install it seems to work. Subsequent attempt fail with a blank page and the following error (no compiler errors):

This started right after 4.19.1 was published yesterday, as soon as people did an npm install.

If the current behavior is a bug, please provide the steps to reproduce.

In our project we see this bug on all computers, and the fix is the same. To explicitly npm install webpack@4.19.0 after the npm install script concludes.

What is the expected behavior?

npx start should always start up the website (not just the first time after a fresh npm install) and not result in a blank page + the error in the screenshot above. .

Other relevant information:
webpack version: 4.19.1
Node.js version: 8.11.4
Operating System: Windows 10 Pro 64 Bit
Additional tools:

"webpack-cli": "^3.0.8",
"webpack-dev-server": "^3.1.4",
"webpack-hot-middleware": "^2.22.2",
"webpack-merge": "^4.1.3"

[ooflorent]

Thanks for your report. It would be great if you reduce your issue to a small reproducible example. Best put this example into a github repository together with instructions how to get to the problem.

[shincysl]

Not sure if this is the same issue. We use hard-source plugin. The first time, webpack compiles successfully. But when run webpack again, there are syntax errors in the emitted code. The problem code looks like "undefinedfunction".
There are no changes in hard-source plugin. We just updated webpack from 4.19.0 to 4.19.1.

[mape]

I'm having the same issue as @shincysl when using the hard-source plugin after updating from 4.19.0 to 4.19.1. I tried creating a barebone project to reproduce the issue but for whatever reason it doesn't show the same symptoms as my main project.

[ooflorent]

Could you confirm the error is gone if you remove hard-source-webpack-plugin?

[sorenhoyer]

Great! The common denominator seems to be hard-source-webpack-plugin - we also use that (latest version 0.12.0)! @ooflorent It does indeed seem to be working fine without it - just tested.

[sokra]

@mzgoddard Do you know what causes this? Maybe we can find a backward-compatible change.

[kirschre]

@ooflorent @sokra I'm running into the same issue as the users above. Little bit of extra debugging info - it seems hard-source-webpack-plugin can occasionally cause dep.prefix to be undefined here, which ends up getting directly inserted into the string output. Not sure why yet but I'll try to dig a little further.

[domoritz]

I'm getting an error Uncaught SyntaxError: Unexpected token { with this code:

/***/ "./node_modules/d3-array/src/ascending.js":
/***/ (function(module, __webpack_exports__, __webpack_require__) {

"use strict";
__webpack_require__.r(__webpack_exports__);
/* harmony default export */ __webpack_exports__["default"] = (undefinedfunction(a, b) {
  return a < b ? -1 : a > b ? 1 : a >= b ? 0 : NaN;
});


/***/ }),

Yes, I am also using hard-source.

[anton164]

We're getting:

ERROR in chunk 4
4.b85a368070f1993f5b0b.js
/root/project/node_modules/recharts/es6/index.js 41315544f420ae398c27b28733ff9346
Unexpected token (1:91)
| /* harmony default export */ var __WEBPACK_MODULE_DEFAULT_EXPORT__ = (undefinedfunction(x) {
|   return function constant() {
|     return x;

and

with hard-source-webpack-plugin and webpack 4.20.2

[sokra]

There is already a PR in hard-source-webpack-plugin fixing this: mzgoddard/hard-source-webpack-plugin#444

Sorry that this is causing issues, hard-source-webpack-plugin relies on webpack internals for serialization. Internals may change in non-major version so it's a bit harder to keep in sync...

The situation will probably improve with webpack 5, which includes persistent caching in the core.

[sh4d1t0]

I reverted to 4.19.0 and not working in production enviroment, 4.17.1 neither, only develop enviroment.

So I deleted hard-source-webpack-plugin and works again

[sibelius]

it is a problem with hard-source-webpack-plugin

[sibelius]

@sokra we can close this, this happens because of an old cache when using hard-source-webpack-plugin