bootstrap-loader: "Error: Path must be a string. Received undefined" updating to webpack 2.1.0-beta.25

Thought my issue was related to another thread, but it seems they are separate, so I’m opening up this ticket. Still actively trying to figure out what exactly is happening here. There were some breaking changes between webpack 2.1.0-beta.23-25, and upgrading is producing an error from bootstrap-loader…

69% building modules 1174/1175 modules 1 active ...ode_modules/bootstrap-loader/no-op.jsTypeError: Path must be a string. Received undefined
    at assertPath (path.js:8:11)
    at Object.posix.relative (path.js:495:3)
    at Object.onRender (/home/p3pt/dev/java/projects/spring-boot-angular2/frontend/node_modules/sass-loader/index.js:282:42)
    at Object.<anonymous> (/home/p3pt/dev/java/projects/spring-boot-angular2/frontend/node_modules/sass-loader/node_modules/async/dist/async.js:2414:31)
    at apply (/home/p3pt/dev/java/projects/spring-boot-angular2/frontend/node_modules/sass-loader/node_modules/async/dist/async.js:40:25)
    at Object.<anonymous> (/home/p3pt/dev/java/projects/spring-boot-angular2/frontend/node_modules/sass-loader/node_modules/async/dist/async.js:76:12)
    at Object.callback (/home/p3pt/dev/java/projects/spring-boot-angular2/frontend/node_modules/sass-loader/node_modules/async/dist/async.js:988:16)
    at options.success (/home/p3pt/dev/java/projects/spring-boot-angular2/frontend/node_modules/node-sass/lib/index.js:309:32)

I am not completely sure that the issue is bootstrap-loader, I feel as though it may just be a configuration problem, or even possibly an issue with sass-loader (given the error trace)

I pulled the basic example and tried to reproduce the issue, but could not, even updating the webpack version to 2.1.0-beta.25 did not break the build. Scratching my head here on this one a bit.

I’m still debugging, and searching around for a solution. I will definitely submit a PR if I find the fix is related to bootstrap-loader.

For reference… webpack.common.js

const webpack = require('webpack');
const CopyWebpackPlugin = require('copy-webpack-plugin');
const HtmlWebpackPlugin = require('html-webpack-plugin');
const ExtractTextPlugin = require('extract-text-webpack-plugin');
const helpers = require('./helpers');
const autoprefixer = require('autoprefixer');

module.exports = {
    entry: {
        'polyfills': './src/polyfills.ts',
        'vendor': './src/vendor.ts',
        'app': './src/main.ts'
    },

    context: helpers.root(),

    resolve: {
        modules: [helpers.root('src'), "node_modules"],
        descriptionFiles: ['package.json'],
        extensions: ['.js', '.ts', '.css', '.scss', '.json', '.html']
    },

    module: {
      rules: [
          {
            enforce: 'pre',
            test: /\.js$/,
            loader: 'source-map-loader',
            exclude: [helpers.root('node_modules')]
          },

          {
            test: /\.ts$/,
            loaders: ['awesome-typescript-loader', 'angular2-template-loader'],
            exclude: [/\.(spec|e2e)\.ts$/]
          },

          {
            test: /\.html$/,
            loader: 'raw-loader',
            exclude: [helpers.root('src/index.html')]
          },

          {
            test: /\.css$/,
            loader: 'raw-loader!style-loader!css-loader!postcss-loader'
          },

          {
            test: /initial\.scss$/,
            loader: ExtractTextPlugin.extract({ fallbackLoader: 'style-loader', loader: 'css-loader!sass-loader'})
          },

          {
            test: /\.scss$/,
            loaders: ['raw-loader', 'sass-loader'],
            exclude: [helpers.root('node_modules')]
          },

          {
            test: /\.woff(2)?(\?v=[0-9]\.[0-9]\.[0-9])?$/,
            loader: "url-loader?limit=10000&mimetype=application/font-woff"
          },

          {
              test: /\.(ttf|eot|svg)(\?v=[0-9]\.[0-9]\.[0-9])?$/,
              loader: "file-loader"
          },

          {
            test: /\.json$/,
            loader: 'json-loader'
          },

          {
            test: /bootstrap\/dist\/js\/umd\//,
            loader: 'imports?jQuery=jquery'
          }
      ]
    },

    plugins: [
        new webpack.ContextReplacementPlugin(
            /angular(\\|\/)core(\\|\/)(esm(\\|\/)src|src)(\\|\/)linker/,
            __dirname
        ),
        new ExtractTextPlugin({
            filename: 'css/[name].css',
            disable: false, allChunks: true
        }),

        new webpack.optimize.CommonsChunkPlugin({
            name: ['app', 'vendor', 'polyfills']
        }),

        new CopyWebpackPlugin([{
          from: 'src/assets',
          to: 'assets'
        }]),

        new HtmlWebpackPlugin({
            template: 'src/index.html',
            chunksSortMode: 'dependency'
        }),

        new webpack.ProvidePlugin({
            jQuery: 'jquery',
            $: 'jquery',
            jquery: 'jquery',
            "window.moment": "moment",
            'Tether': 'tether',
            'window.Tether': 'tether',
            Tooltip: "exports?Tooltip!bootstrap/js/dist/tooltip",
            Alert: "exports?Alert!bootstrap/js/dist/alert",
            Button: "exports?Button!bootstrap/js/dist/button",
            Carousel: "exports?Carousel!bootstrap/js/dist/carousel",
            Collapse: "exports?Collapse!bootstrap/js/dist/collapse",
            Dropdown: "exports?Dropdown!bootstrap/js/dist/dropdown",
            Modal: "exports?Modal!bootstrap/js/dist/modal",
            Popover: "exports?Popover!bootstrap/js/dist/popover",
            Scrollspy: "exports?Scrollspy!bootstrap/js/dist/scrollspy",
            Tab: "exports?Tab!bootstrap/js/dist/tab",
            Util: "exports?Util!bootstrap/js/dist/util"
        }),

        new webpack.LoaderOptionsPlugin({
          options: {
            postcss: [autoprefixer]
          }
        })
    ],

    node: {
        fs: 'empty',
        global: true,
        crypto: 'empty',
        module: false,
        clearImmediate: false,
        setImmediate: false
    }
};