modified

build/node_modules/css-tree/lib/utils/createCustomError.js

@@ -0,0 +1,17 @@
+module.exports = function createCustomError(name, message) {
+    // use Object.create(), because some VMs prevent setting line/column otherwise
+    // (iOS Safari 10 even throws an exception)
+    var error = Object.create(SyntaxError.prototype);
+    var errorStack = new Error();
+
+    error.name = name;
+    error.message = message;
+
+    Object.defineProperty(error, 'stack', {
+        get: function() {
+            return (errorStack.stack || '').replace(/^(.+\n){1,3}/, name + ': ' + message + '\n');
+        }
+    });
+
+    return error;
+};