Include stdout in codesign failure output

packages/flutter_tools/lib/src/build_system/targets/ios.dart

@@ -711,6 +711,16 @@ void _signFramework(Environment environment, String binaryPath, BuildMode buildM
     binaryPath,
   ]);
   if (result.exitCode != 0) {
-    throw Exception('Failed to codesign $binaryPath with identity $codesignIdentity.\n${result.stderr}');
+    final String stdout = (result.stdout as String).trim();
+    final String stderr = (result.stderr as String).trim();
+    final StringBuffer output = StringBuffer();
+    output.writeln('Failed to codesign $binaryPath with identity $codesignIdentity.');
+    if (stdout.isNotEmpty) {
+      output.writeln(stdout);
+    }
+    if (stderr.isNotEmpty) {
+      output.writeln(stderr);
+    }
+    throw Exception(output.toString());
   }
 }

packages/flutter_tools/test/general.shard/build_system/targets/ios_test.dart

@@ -836,21 +836,25 @@ void main() {
         lipoCommandNonFatResult,
         lipoVerifyArm64Command,
         FakeCommand(command: <String>[
-          'codesign',
-          '--force',
-          '--sign',
-          'ABC123',
-          '--timestamp=none',
-          binary.path,
-        ], exitCode: 1, stderr: 'codesign error'),
+            'codesign',
+            '--force',
+            '--sign',
+            'ABC123',
+            '--timestamp=none',
+            binary.path,
+          ],
+          exitCode: 1,
+          stderr: 'codesign error',
+          stdout: 'codesign info',
+        ),
       ]);
 
       await expectLater(
         const DebugUnpackIOS().build(environment),
         throwsA(isException.having(
           (Exception exception) => exception.toString(),
           'description',
-          contains('Failed to codesign output/Flutter.framework/Flutter with identity ABC123.\ncodesign error'),
+          contains('Failed to codesign output/Flutter.framework/Flutter with identity ABC123.\ncodesign info\ncodesign error'),
         )),
       );