Merge pull request #15578 from webpack/feat/catch-error-in-run-as-child

catch error in runAsChild callback

lib/Compiler.js

@@ -545,8 +545,21 @@ class Compiler {
 	 */
 	runAsChild(callback) {
 		const startTime = Date.now();
+
+		const finalCallback = (err, entries, compilation) => {
+			try {
+				callback(err, entries, compilation);
+			} catch (e) {
+				const err = new WebpackError(
+					`compiler.runAsChild callback error: ${e}`
+				);
+				err.details = e.stack;
+				this.parentCompilation.errors.push(err);
+			}
+		};
+
 		this.compile((err, compilation) => {
-			if (err) return callback(err);
+			if (err) return finalCallback(err);
 
 			this.parentCompilation.children.push(compilation);
 			for (const { name, source, info } of compilation.getAssets()) {
@@ -561,7 +574,7 @@ class Compiler {
 			compilation.startTime = startTime;
 			compilation.endTime = Date.now();
 
-			return callback(null, entries, compilation);
+			return finalCallback(null, entries, compilation);
 		});
 	}