print file/location/frame when encountering an initial error in dev

src/api/dev.ts

@@ -199,9 +199,10 @@ class Watcher extends EventEmitter {
 						});
 
 						manifest_data = new_manifest_data;
-					} catch (err) {
+					} catch (error) {
 						this.emit('error', <ErrorEvent>{
-							message: err.message
+							type: 'manifest',
+							error
 						});
 					}
 				}
@@ -408,11 +409,11 @@ class Watcher extends EventEmitter {
 	}) {
 		compiler.oninvalid(invalid);
 
-		compiler.watch((err?: Error, result?: CompileResult) => {
+		compiler.watch((error?: Error, result?: CompileResult) => {
-			if (err) {
+			if (error) {
 				this.emit('error', <ErrorEvent>{
 					type: name,
-					message: err.message
+					error
 				});
 			} else {
 				this.emit('build', {

src/cli.ts

@@ -89,8 +89,17 @@ prog.command('dev')
 			});
 
 			watcher.on('error', (event: ErrorEvent) => {
-				console.log(colors.red(`✗ ${event.type}`));
+				const { type, error } = event;
-				console.log(colors.red(event.message));
+
+				console.log(colors.bold().red(`✗ ${type}`));
+
+				if (error.loc) {
+					let file = error.loc.file && `${path.relative(process.cwd(), error.loc.file)} (${error.loc.line}:${error.loc.column})`;
+					if (file) console.log(colors.bold(file));
+				}
+
+				console.log(colors.red(event.error.message));
+				if (error.frame) console.log(error.frame);
 			});
 
 			watcher.on('fatal', (event: FatalEvent) => {

src/interfaces.ts

@@ -69,7 +69,7 @@ export type ReadyEvent = {
 
 export type ErrorEvent = {
 	type: string;
-	message: string;
+	error: Error;
 };
 
 export type FatalEvent = {