errors - fix stack printing

src/vs/base/common/errorMessage.ts

@@ -10,7 +10,7 @@ import * as arrays from 'vs/base/common/arrays';
 function exceptionToErrorMessage(exception: any, verbose: boolean): string {
 	if (exception.message) {
 		if (verbose && (exception.stack || exception.stacktrace)) {
-			return nls.localize('stackTrace.format', "{0}: {1}", detectSystemErrorMessage(exception), exception.stack || exception.stacktrace);
+			return nls.localize('stackTrace.format', "{0}: {1}", detectSystemErrorMessage(exception), stackToString(exception.stack) || stackToString(exception.stacktrace));
 		}
 
 		return detectSystemErrorMessage(exception);
@@ -19,6 +19,14 @@ function exceptionToErrorMessage(exception: any, verbose: boolean): string {
 	return nls.localize('error.defaultMessage', "An unknown error occurred. Please consult the log for more details.");
 }
 
+function stackToString(stack: string[] | string | undefined): string | undefined {
+	if (Array.isArray(stack)) {
+		return stack.join('\n');
+	}
+
+	return stack;
+}
+
 function detectSystemErrorMessage(exception: any): string {
 
 	// See https://nodejs.org/api/errors.html#errors_class_system_error