[Pkg-javascript-devel] Bug#960901: webpack: Resolver falsely detects phantom ‘buffer’ import in ‘clone’ library

[Ben Finney]

Package: webpack
Version: 4.43.0-1
Severity: normal

When I create a minimal project that imports the ‘clone’ library,
Webpack reports that it cannot resolve an import of ‘buffer’:

=====
ERROR in /usr/share/nodejs/clone/clone.js
Module not found: Error: Can't resolve './../../../../tmp/app-using-clone.AIFQnn/buffer' in '/usr/share/nodejs/clone'
 @ /usr/share/nodejs/clone/clone.js 1:0-58
 @ ./source/main.js
=====

There is no attempt in that library to import ‘buffer’. The path in
the error message should never be used and is not present in the
‘clone’ library.

The ‘clone’ library is the ‘/usr/share/nodejs/clone/clone.js’
installed from Debian.

Webpack is not reporting correctly where it is finding this import. So
it is not clear, from that error message, what is causing Webpack to
detect a ‘buffer’ name that it then cannot resolve.


Here is a demonstration of how I invoked the above error:

=====
$ dpkg-query --list node-clone | grep '^i'
ii  node-clone     2.1.2-2      all          deep cloning of objects and arrays

$ cd $(mktemp --tmpdir --directory 'app-using-clone.XXXXXX')

$ mkdir source/
$ cat > source/main.js
"use strict";
import clone from 'clone';

$ cat > webpack-config.js
"use strict";

const path = require('path');

const rootDir = path.resolve(__dirname);
const sourceDir = path.resolve(rootDir, 'source');
const buildDir = path.resolve(rootDir, 'build');

module.exports = {
    mode: 'development',
    entry: {
        app: path.resolve(sourceDir, 'main.js'),
    },
    output: {
        path: buildDir,
        filename: 'app.js',
    },
    resolve: {
        modules: [
            sourceDir,
            '/usr/share/javascript',
            '/usr/share/nodejs',
        ],
    },
};

$ webpack --config webpack-config.js
Hash: eceaa9ff3519c5b14efb
Version: webpack 4.43.0
Time: 111ms
Built at: 18/05/2020 1:09:24 pm
 Asset      Size  Chunks             Chunk Names
app.js  12.1 KiB     app  [emitted]  app
Entrypoint app = app.js
[../../usr/share/nodejs/clone/clone.js]
/usr/share/nodejs/clone/clone.js 7.12 KiB {app} [built]
[./source/main.js] 42 bytes {app} [built]

ERROR in /usr/share/nodejs/clone/clone.js
Module not found: Error: Can't resolve
'./../../../../tmp/app-using-clone.AIFQnn/buffer' in
'/usr/share/nodejs/clone'
 @ /usr/share/nodejs/clone/clone.js 1:0-58
 @ ./source/main.js

$
=====


-- System Information:
Debian Release: bullseye/sid
  APT prefers testing
  APT policy: (500, 'testing')
Architecture: amd64 (x86_64)

Kernel: Linux 5.6.0-1-amd64 (SMP w/8 CPU cores)
Locale: LANG=en_AU.UTF-8, LC_CTYPE=en_AU.UTF-8 (charmap=UTF-8) (ignored: LC_ALL set to en_AU.UTF-8), LANGUAGE=en_AU.UTF-8 (charmap=UTF-8) (ignored: LC_ALL set to en_AU.UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled

Versions of packages webpack depends on:
ii  node-ajv                           6.10.2-1
ii  node-ajv-keywords                  3.4.1-1
ii  node-anymatch                      3.1.1+~2.1.1-1
ii  node-debbundle-acorn [node-acorn]  6.2.1+ds+~cs11.24.3-3
ii  node-enhanced-resolve              4.1.0-4
ii  node-esrecurse                     4.2.1-1
ii  node-estraverse                    4.2.0-1
ii  node-findup-sync                   4.0.0-3
ii  node-interpret                     1.0.1-1
ii  node-json-parse-better-errors      1.0.2-2
ii  node-libs-browser                  2.2.1-3
ii  node-loader-runner                 2.3.0-2
ii  node-loader-utils                  1.2.3-1
ii  node-memory-fs                     0.4.1-2
ii  node-micromatch                    4.0.2+repack-3
ii  node-mkdirp                        0.5.1-2
ii  node-neo-async                     2.6.1-3
ii  node-resolve-cwd                   2.0.0-2
ii  node-schema-utils                  1.0.0-2
ii  node-supports-color                6.1.0-2
ii  node-tapable                       1.0.0-4
ii  node-uglifyjs-webpack-plugin       1.3.0-6
ii  node-watchpack                     1.6.0-2
ii  node-webassemblyjs                 1.9.0+dfsg-4
ii  node-webpack-sources               1.1.0-2
ii  node-yargs                         15.3.0-1
ii  nodejs                             10.20.1~dfsg-1

webpack recommends no packages.

webpack suggests no packages.

-- no debconf information

-- 
 \            “Politics is not the art of the possible. It consists in |
  `\       choosing between the disastrous and the unpalatable.” —John |
_o__)                                    Kenneth Galbraith, 1962-03-02 |
Ben Finney <bignose at debian.org>
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