babel-loader: Error: fileSystem.statSync is not a function in 7.1.2

I’m submitting a bug report

Webpack Version: 1.15.0

Babel Core Version: 6.26.0

Babel Loader Version: 7.1.2

Please tell us about your environment: OSX 10.12.6

Current behavior: I’m getting following error when building with gulp and webpack:

[12:52:08] Using gulpfile gulpfile.js
[12:52:08] Starting 'build'...
[12:52:09] Version: webpack 1.15.0

ERROR in ./src/entry.js
Module build failed: TypeError: fileSystem.statSync is not a function
    at module.exports (node_modules/babel-loader/lib/utils/exists.js:7:25)
    at find (node_modules/babel-loader/lib/resolve-rc.js:13:9)
    at Object.module.exports (node_modules/babel-loader/lib/index.js:113:132)
[12:52:09] Finished 'build' after 1.17 s

Gulp ran 1 task in 1.17 s

Here is my Gulp script:

module.exports = function (gulp, config, plugins) {
  return function () {
    return gulp.src(config.sources.concat(config.lib))
      .pipe(plugins.webpack({
        entry: config.entry,
        output: {
          filename: 'lib.js',
          library: 'lib',
          libraryTarget: 'var'
        },
        module: {
          loaders: [{
            test: /.js$/,
            loader: 'babel-loader',
            exclude: /node_modules/,
            query: {
              presets: ['es2015']
            }
          }]
        },
        node: {
          fs: 'empty'
        }
      }))
      .pipe(gulp.dest(config.dist + 'js/'));
  };
};

In version 7.1.1 of babel-loader the problem did not occur. The reason is probably because all errors in exists.js are swallowed in 7.1.1:

  try {
    exists = fileSystem.statSync(filename).isFile();
  } catch (e) {}

When I remove try & catch in 7.1.1, I’m getting the same error as in 7.1.2.