Вынес dev-middleware в dev.js, теперь игнорируется сборщиком pkg

server/dev.js

@@ -0,0 +1,22 @@
+const log = require('./core/getLogger').getLog();
+
+function webpackDevMiddleware(app) {
+    const webpack  = require('webpack');
+    const wpConfig = require('../build/webpack.dev.config');
+
+    const compiler = webpack(wpConfig);
+    const devMiddleware = require('webpack-dev-middleware');
+    app.use(devMiddleware(compiler, {
+        publicPath: wpConfig.output.publicPath,
+        stats: {colors: true}
+    }));
+
+    let hotMiddleware = require('webpack-hot-middleware');
+    app.use(hotMiddleware(compiler, {
+        log: log
+    }));
+}
+
+module.exports = {
+    webpackDevMiddleware
+};

server/index.js

@@ -16,20 +16,8 @@ async function main() {
     await connPool.init();
 
     if (config.branch == 'development') {
-        const webpack  = require('webpack');
-        const wpConfig = require('../build/webpack.dev.config');
-
-        const compiler = webpack(wpConfig);
-        const devMiddleware = require('webpack-dev-middleware');
-        app.use(devMiddleware(compiler, {
-            publicPath: wpConfig.output.publicPath,
-            stats: {colors: true}
-        }));
-
-        let hotMiddleware = require('webpack-hot-middleware');
-        app.use(hotMiddleware(compiler, {
-            log: log
-        }));
+        const devFileName = './dev.js'; //ignored by pkg
+        require(devFileName).webpackDevMiddleware(app);
     }
 
     app.use(express.static(config.publicDir));