Stackman does not resolve filename (path) of sourcemap generated by webpack

[kerwanp]

Description of the issue

Stackman generate a wrong filepath when the sourcemap is generated with Webpack and using webpack:// URLs.

For example, the error triggered when using elastic-apm-node with Webpack & Typescript:

[...]
this.apmAgent.captureError(err);
[...]

error while getting callsite source context: ENOENT: no such file or directory, open '/home/kerwan/workspace/kmp-agency/kmp-flow-launcher/dist/webpack:/boilerplate-node-typescript/src/launchers/webhooks/webhook.launcher.ts'
error while getting callsite source context: ENOENT: no such file or directory, open '/home/kerwan/workspace/kmp-agency/kmp-flow-launcher/dist/webpack:/boilerplate-node-typescript/src/launchers/webhooks/abstract-webhook.launcher.ts'
error while getting callsite source context: ENOENT: no such file or directory, open '/home/kerwan/workspace/kmp-agency/kmp-flow-launcher/dist/webpack:/boilerplate-node-typescript/src/services/webpack:/boilerplate-node-typescript/src/app.ts'
error while getting callsite source context: ENOENT: no such file or directory, open '/home/kerwan/workspace/kmp-agency/kmp-flow-launcher/dist/webpack:/boilerplate-node-typescript/src/services/webpack:/boilerplate-node-typescript/src/app.ts'

---

For example, the sourcemap URL for webpack://boilerplate-node-typescript/./src/launchers/abstract-launcher.ts
is resolved to /home/kerwan/workspace/kmp-agency/kmp-flow-launcher/dist/webpack:/boilerplate-node-typescript/src/launchers/webhooks/webhook.launcher.ts
when it should be /home/kerwan/workspace/kmp-agency/kmp-flow-launcher/src/launchers/webhooks/webhook.launcher.ts.

Steps to reproduce

Setup a project with webpack, typescript and ts-loader with the following configuration:

package.json:

{
  [...]
  "devDependencies": {
    "ts-loader": "^8.0.11",
    "typescript": "^4.1.2",
    "webpack": "^5.10.0",
    "webpack-cli": "^4.2.0",
  },
  "dependencies": {
    "stackman": "^4.0.1"
  }
  [...]
}

webpack.config.js:

const path = require('path')

const {NODE_ENV} = process.env

module.exports = {
  mode: NODE_ENV,
  target: 'node',
  devtool: 'source-map',
  entry: path.resolve(__dirname, 'src/app.ts'),
  output: {
    path: path.resolve(__dirname, 'dist'),
  },
  module: {
    rules: [
      {
        test: /.ts$/,
        include: /src/,
        loader: 'ts-loader'
      }
    ]
  },
  resolve: {
    extensions: ['.ts', '.js', '.json']
  },
}

With this configuration it will generate in the folder dist the file main.js and the sourcemap main.js.map.

Workaround

Temporarily, we have changed the devtool config in webpack to use relative paths without the namespace:

module.exports = {
  output: {
    path: path.resolve(__dirname, 'dist'),
    devtoolFallbackModuleFilenameTemplate: '../[resource-path]',
    devtoolModuleFilenameTemplate: '../[resource-path]'
  },
}