[Core] Improve error messages with vformat

Author: AThousandShips

core/config/project_settings.cpp

@@ -214,36 +214,36 @@ String ProjectSettings::localize_path(const String &p_path) const {
 }
 
 void ProjectSettings::set_initial_value(const String &p_name, const Variant &p_value) {
-	ERR_FAIL_COND_MSG(!props.has(p_name), "Request for nonexistent project setting: " + p_name + ".");
+	ERR_FAIL_COND_MSG(!props.has(p_name), vformat("Request for nonexistent project setting: '%s'.", p_name));
 
 	// Duplicate so that if value is array or dictionary, changing the setting will not change the stored initial value.
 	props[p_name].initial = p_value.duplicate();
 }
 
 void ProjectSettings::set_restart_if_changed(const String &p_name, bool p_restart) {
-	ERR_FAIL_COND_MSG(!props.has(p_name), "Request for nonexistent project setting: " + p_name + ".");
+	ERR_FAIL_COND_MSG(!props.has(p_name), vformat("Request for nonexistent project setting: '%s'.", p_name));
 	props[p_name].restart_if_changed = p_restart;
 }
 
 void ProjectSettings::set_as_basic(const String &p_name, bool p_basic) {
-	ERR_FAIL_COND_MSG(!props.has(p_name), "Request for nonexistent project setting: " + p_name + ".");
+	ERR_FAIL_COND_MSG(!props.has(p_name), vformat("Request for nonexistent project setting: '%s'.", p_name));
 	props[p_name].basic = p_basic;
 }
 
 void ProjectSettings::set_as_internal(const String &p_name, bool p_internal) {
-	ERR_FAIL_COND_MSG(!props.has(p_name), "Request for nonexistent project setting: " + p_name + ".");
+	ERR_FAIL_COND_MSG(!props.has(p_name), vformat("Request for nonexistent project setting: '%s'.", p_name));
 	props[p_name].internal = p_internal;
 }
 
 void ProjectSettings::set_ignore_value_in_docs(const String &p_name, bool p_ignore) {
-	ERR_FAIL_COND_MSG(!props.has(p_name), "Request for nonexistent project setting: " + p_name + ".");
+	ERR_FAIL_COND_MSG(!props.has(p_name), vformat("Request for nonexistent project setting: '%s'.", p_name));
 #ifdef DEBUG_METHODS_ENABLED
 	props[p_name].ignore_value_in_docs = p_ignore;
 #endif
 }
 
 bool ProjectSettings::get_ignore_value_in_docs(const String &p_name) const {
-	ERR_FAIL_COND_V_MSG(!props.has(p_name), false, "Request for nonexistent project setting: " + p_name + ".");
+	ERR_FAIL_COND_V_MSG(!props.has(p_name), false, vformat("Request for nonexistent project setting: '%s'.", p_name));
 #ifdef DEBUG_METHODS_ENABLED
 	return props[p_name].ignore_value_in_docs;
 #else
@@ -371,7 +371,7 @@ Variant ProjectSettings::get_setting_with_override(const StringName &p_name) con
 	}
 
 	if (!props.has(name)) {
-		WARN_PRINT("Property not found: " + String(name));
+		WARN_PRINT(vformat("Property not found: '%s'.", String(name)));
 		return Variant();
 	}
 	return props[name].variant;
@@ -565,7 +565,7 @@ Error ProjectSettings::_setup(const String &p_path, const String &p_main_pack, b
 
 	if (!p_main_pack.is_empty()) {
 		bool ok = _load_resource_pack(p_main_pack);
-		ERR_FAIL_COND_V_MSG(!ok, ERR_CANT_OPEN, "Cannot open resource pack '" + p_main_pack + "'.");
+		ERR_FAIL_COND_V_MSG(!ok, ERR_CANT_OPEN, vformat("Cannot open resource pack '%s'.", p_main_pack));
 
 		Error err = _load_settings_text_or_binary("res://project.godot", "res://project.binary");
 		if (err == OK && !p_ignore_override) {
@@ -644,7 +644,7 @@ Error ProjectSettings::_setup(const String &p_path, const String &p_main_pack, b
 	// or, if requested (`p_upwards`) in parent directories.
 
 	Ref<DirAccess> d = DirAccess::create(DirAccess::ACCESS_FILESYSTEM);
-	ERR_FAIL_COND_V_MSG(d.is_null(), ERR_CANT_CREATE, "Cannot create DirAccess for path '" + p_path + "'.");
+	ERR_FAIL_COND_V_MSG(d.is_null(), ERR_CANT_CREATE, vformat("Cannot create DirAccess for path '%s'.", p_path));
 	d->change_dir(p_path);
 
 	String current_dir = d->get_current_dir();
@@ -748,7 +748,7 @@ Error ProjectSettings::_load_settings_binary(const String &p_path) {
 		f->get_buffer(d.ptrw(), vlen);
 		Variant value;
 		err = decode_variant(value, d.ptr(), d.size(), nullptr, true);
-		ERR_CONTINUE_MSG(err != OK, "Error decoding property: " + key + ".");
+		ERR_CONTINUE_MSG(err != OK, vformat("Error decoding property: '%s'.", key));
 		set(key, value);
 	}
 
@@ -790,7 +790,7 @@ Error ProjectSettings::_load_settings_text(const String &p_path) {
 			last_save_time = FileAccess::get_modified_time(get_resource_path().path_join("project.godot"));
 			return OK;
 		}
-		ERR_FAIL_COND_V_MSG(err != OK, err, "Error parsing " + p_path + " at line " + itos(lines) + ": " + error_text + " File might be corrupted.");
+		ERR_FAIL_COND_V_MSG(err != OK, err, vformat("Error parsing '%s' at line %d: %s File might be corrupted.", p_path, lines, error_text));
 
 		if (!assign.is_empty()) {
 			if (section.is_empty() && assign == "config_version") {
@@ -816,15 +816,15 @@ Error ProjectSettings::_load_settings_text_or_binary(const String &p_text_path,
 		return OK;
 	} else if (err != ERR_FILE_NOT_FOUND) {
 		// If the file exists but can't be loaded, we want to know it.
-		ERR_PRINT("Couldn't load file '" + p_bin_path + "', error code " + itos(err) + ".");
+		ERR_PRINT(vformat("Couldn't load file '%s', error code %d.", p_bin_path, err));
 	}
 
 	// Fallback to text-based project.godot file if binary was not found.
 	err = _load_settings_text(p_text_path);
 	if (err == OK) {
 		return OK;
 	} else if (err != ERR_FILE_NOT_FOUND) {
-		ERR_PRINT("Couldn't load file '" + p_text_path + "', error code " + itos(err) + ".");
+		ERR_PRINT(vformat("Couldn't load file '%s', error code %d.", p_text_path, err));
 	}
 
 	return err;
@@ -838,30 +838,30 @@ Error ProjectSettings::load_custom(const String &p_path) {
 }
 
 int ProjectSettings::get_order(const String &p_name) const {
-	ERR_FAIL_COND_V_MSG(!props.has(p_name), -1, "Request for nonexistent project setting: " + p_name + ".");
+	ERR_FAIL_COND_V_MSG(!props.has(p_name), -1, vformat("Request for nonexistent project setting: '%s'.", p_name));
 	return props[p_name].order;
 }
 
 void ProjectSettings::set_order(const String &p_name, int p_order) {
-	ERR_FAIL_COND_MSG(!props.has(p_name), "Request for nonexistent project setting: " + p_name + ".");
+	ERR_FAIL_COND_MSG(!props.has(p_name), vformat("Request for nonexistent project setting: '%s'.", p_name));
 	props[p_name].order = p_order;
 }
 
 void ProjectSettings::set_builtin_order(const String &p_name) {
-	ERR_FAIL_COND_MSG(!props.has(p_name), "Request for nonexistent project setting: " + p_name + ".");
+	ERR_FAIL_COND_MSG(!props.has(p_name), vformat("Request for nonexistent project setting: '%s'.", p_name));
 	if (props[p_name].order >= NO_BUILTIN_ORDER_BASE) {
 		props[p_name].order = last_builtin_order++;
 	}
 }
 
 bool ProjectSettings::is_builtin_setting(const String &p_name) const {
 	// Return true because a false negative is worse than a false positive.
-	ERR_FAIL_COND_V_MSG(!props.has(p_name), true, "Request for nonexistent project setting: " + p_name + ".");
+	ERR_FAIL_COND_V_MSG(!props.has(p_name), true, vformat("Request for nonexistent project setting: '%s'.", p_name));
 	return props[p_name].order < NO_BUILTIN_ORDER_BASE;
 }
 
 void ProjectSettings::clear(const String &p_name) {
-	ERR_FAIL_COND_MSG(!props.has(p_name), "Request for nonexistent project setting: " + p_name + ".");
+	ERR_FAIL_COND_MSG(!props.has(p_name), vformat("Request for nonexistent project setting: '%s'.", p_name));
 	props.erase(p_name);
 }
 
@@ -876,7 +876,7 @@ Error ProjectSettings::save() {
 Error ProjectSettings::_save_settings_binary(const String &p_file, const RBMap<String, List<String>> &p_props, const CustomMap &p_custom, const String &p_custom_features) {
 	Error err;
 	Ref<FileAccess> file = FileAccess::open(p_file, FileAccess::WRITE, &err);
-	ERR_FAIL_COND_V_MSG(err != OK, err, "Couldn't save project.binary at " + p_file + ".");
+	ERR_FAIL_COND_V_MSG(err != OK, err, vformat("Couldn't save project.binary at '%s'.", p_file));
 
 	uint8_t hdr[4] = { 'E', 'C', 'F', 'G' };
 	file->store_buffer(hdr, 4);
@@ -946,7 +946,7 @@ Error ProjectSettings::_save_settings_text(const String &p_file, const RBMap<Str
 	Error err;
 	Ref<FileAccess> file = FileAccess::open(p_file, FileAccess::WRITE, &err);
 
-	ERR_FAIL_COND_V_MSG(err != OK, err, "Couldn't save project.godot - " + p_file + ".");
+	ERR_FAIL_COND_V_MSG(err != OK, err, vformat("Couldn't save project.godot - %s.", p_file));
 
 	file->store_line("; Engine configuration file.");
 	file->store_line("; It's best edited using the editor UI and not directly,");
@@ -1119,7 +1119,7 @@ Error ProjectSettings::save_custom(const String &p_path, const CustomMap &p_cust
 	} else if (p_path.ends_with(".binary")) {
 		return _save_settings_binary(p_path, save_props, p_custom, save_features);
 	} else {
-		ERR_FAIL_V_MSG(ERR_FILE_UNRECOGNIZED, "Unknown config file format: " + p_path);
+		ERR_FAIL_V_MSG(ERR_FILE_UNRECOGNIZED, vformat("Unknown config file format: '%s'.", p_path));
 	}
 }
 

core/core_bind.cpp

@@ -75,7 +75,7 @@ Ref<Resource> ResourceLoader::load(const String &p_path, const String &p_type_hi
 	Error err = OK;
 	Ref<Resource> ret = ::ResourceLoader::load(p_path, p_type_hint, ResourceFormatLoader::CacheMode(p_cache_mode), &err);
 
-	ERR_FAIL_COND_V_MSG(err != OK, ret, "Error loading resource: '" + p_path + "'.");
+	ERR_FAIL_COND_V_MSG(err != OK, ret, vformat("Error loading resource: '%s'.", p_path));
 	return ret;
 }
 
@@ -1315,7 +1315,7 @@ void Thread::_start_func(void *ud) {
 	}
 
 	if (ce.error != Callable::CallError::CALL_OK) {
-		ERR_FAIL_MSG("Could not call function '" + func_name + "' to start thread " + t->get_id() + ": " + Variant::get_callable_error_text(t->target_callable, nullptr, 0, ce) + ".");
+		ERR_FAIL_MSG(vformat("Could not call function '%s' to start thread %d: %s.", func_name, t->get_id(), Variant::get_callable_error_text(t->target_callable, nullptr, 0, ce)));
 	}
 }
 
@@ -1814,8 +1814,8 @@ Object *Engine::get_singleton_object(const StringName &p_name) const {
 }
 
 void Engine::register_singleton(const StringName &p_name, Object *p_object) {
-	ERR_FAIL_COND_MSG(has_singleton(p_name), "Singleton already registered: " + String(p_name));
-	ERR_FAIL_COND_MSG(!String(p_name).is_valid_ascii_identifier(), "Singleton name is not a valid identifier: " + p_name);
+	ERR_FAIL_COND_MSG(has_singleton(p_name), vformat("Singleton already registered: '%s'.", String(p_name)));
+	ERR_FAIL_COND_MSG(!String(p_name).is_valid_ascii_identifier(), vformat("Singleton name is not a valid identifier: '%s'.", p_name));
 	::Engine::Singleton s;
 	s.class_name = p_name;
 	s.name = p_name;
@@ -1825,8 +1825,8 @@ void Engine::register_singleton(const StringName &p_name, Object *p_object) {
 }
 
 void Engine::unregister_singleton(const StringName &p_name) {
-	ERR_FAIL_COND_MSG(!has_singleton(p_name), "Attempt to remove unregistered singleton: " + String(p_name));
-	ERR_FAIL_COND_MSG(!::Engine::get_singleton()->is_singleton_user_created(p_name), "Attempt to remove non-user created singleton: " + String(p_name));
+	ERR_FAIL_COND_MSG(!has_singleton(p_name), vformat("Attempt to remove unregistered singleton: '%s'.", String(p_name)));
+	ERR_FAIL_COND_MSG(!::Engine::get_singleton()->is_singleton_user_created(p_name), vformat("Attempt to remove non-user created singleton: '%s'.", String(p_name)));
 	::Engine::get_singleton()->remove_singleton(p_name);
 }
 
@@ -1970,14 +1970,14 @@ bool EngineDebugger::is_active() {
 void EngineDebugger::register_profiler(const StringName &p_name, Ref<EngineProfiler> p_profiler) {
 	ERR_FAIL_COND(p_profiler.is_null());
 	ERR_FAIL_COND_MSG(p_profiler->is_bound(), "Profiler already registered.");
-	ERR_FAIL_COND_MSG(profilers.has(p_name) || has_profiler(p_name), "Profiler name already in use: " + p_name);
+	ERR_FAIL_COND_MSG(profilers.has(p_name) || has_profiler(p_name), vformat("Profiler name already in use: '%s'.", p_name));
 	Error err = p_profiler->bind(p_name);
-	ERR_FAIL_COND_MSG(err != OK, "Profiler failed to register with error: " + itos(err));
+	ERR_FAIL_COND_MSG(err != OK, vformat("Profiler failed to register with error: %d.", err));
 	profilers.insert(p_name, p_profiler);
 }
 
 void EngineDebugger::unregister_profiler(const StringName &p_name) {
-	ERR_FAIL_COND_MSG(!profilers.has(p_name), "Profiler not registered: " + p_name);
+	ERR_FAIL_COND_MSG(!profilers.has(p_name), vformat("Profiler not registered: '%s'.", p_name));
 	profilers[p_name]->unbind();
 	profilers.erase(p_name);
 }
@@ -2001,15 +2001,15 @@ void EngineDebugger::profiler_enable(const StringName &p_name, bool p_enabled, c
 }
 
 void EngineDebugger::register_message_capture(const StringName &p_name, const Callable &p_callable) {
-	ERR_FAIL_COND_MSG(captures.has(p_name) || has_capture(p_name), "Capture already registered: " + p_name);
+	ERR_FAIL_COND_MSG(captures.has(p_name) || has_capture(p_name), vformat("Capture already registered: '%s'.", p_name));
 	captures.insert(p_name, p_callable);
 	Callable &c = captures[p_name];
 	::EngineDebugger::Capture capture(&c, &EngineDebugger::call_capture);
 	::EngineDebugger::register_message_capture(p_name, capture);
 }
 
 void EngineDebugger::unregister_message_capture(const StringName &p_name) {
-	ERR_FAIL_COND_MSG(!captures.has(p_name), "Capture not registered: " + p_name);
+	ERR_FAIL_COND_MSG(!captures.has(p_name), vformat("Capture not registered: '%s'.", p_name));
 	::EngineDebugger::unregister_message_capture(p_name);
 	captures.erase(p_name);
 }
@@ -2043,8 +2043,8 @@ Error EngineDebugger::call_capture(void *p_user, const String &p_cmd, const Arra
 	Variant retval;
 	Callable::CallError err;
 	capture.callp(args, 2, retval, err);
-	ERR_FAIL_COND_V_MSG(err.error != Callable::CallError::CALL_OK, FAILED, "Error calling 'capture' to callable: " + Variant::get_callable_error_text(capture, args, 2, err));
-	ERR_FAIL_COND_V_MSG(retval.get_type() != Variant::BOOL, FAILED, "Error calling 'capture' to callable: " + String(capture) + ". Return type is not bool.");
+	ERR_FAIL_COND_V_MSG(err.error != Callable::CallError::CALL_OK, FAILED, vformat("Error calling 'capture' to callable: %s.", Variant::get_callable_error_text(capture, args, 2, err)));
+	ERR_FAIL_COND_V_MSG(retval.get_type() != Variant::BOOL, FAILED, vformat("Error calling 'capture' to callable: '%s'. Return type is not bool.", String(capture)));
 	r_captured = retval;
 	return OK;
 }

core/crypto/crypto.cpp

@@ -240,7 +240,7 @@ Error ResourceFormatSaverCrypto::save(const Ref<Resource> &p_resource, const Str
 	} else {
 		ERR_FAIL_V(ERR_INVALID_PARAMETER);
 	}
-	ERR_FAIL_COND_V_MSG(err != OK, err, "Cannot save Crypto resource to file '" + p_path + "'.");
+	ERR_FAIL_COND_V_MSG(err != OK, err, vformat("Cannot save Crypto resource to file '%s'.", p_path));
 	return OK;
 }
 

core/crypto/crypto_core.cpp

@@ -70,15 +70,15 @@ int CryptoCore::RandomGenerator::_entropy_poll(void *p_data, unsigned char *r_bu
 Error CryptoCore::RandomGenerator::init() {
 	int ret = mbedtls_ctr_drbg_seed((mbedtls_ctr_drbg_context *)ctx, mbedtls_entropy_func, (mbedtls_entropy_context *)entropy, nullptr, 0);
 	if (ret) {
-		ERR_FAIL_COND_V_MSG(ret, FAILED, " failed\n  ! mbedtls_ctr_drbg_seed returned an error" + itos(ret));
+		ERR_FAIL_COND_V_MSG(ret, FAILED, vformat(" failed\n  ! mbedtls_ctr_drbg_seed returned an error %d.", ret));
 	}
 	return OK;
 }
 
 Error CryptoCore::RandomGenerator::get_random_bytes(uint8_t *r_buffer, size_t p_bytes) {
 	ERR_FAIL_NULL_V(ctx, ERR_UNCONFIGURED);
 	int ret = mbedtls_ctr_drbg_random((mbedtls_ctr_drbg_context *)ctx, r_buffer, p_bytes);
-	ERR_FAIL_COND_V_MSG(ret, FAILED, " failed\n  ! mbedtls_ctr_drbg_seed returned an error" + itos(ret));
+	ERR_FAIL_COND_V_MSG(ret, FAILED, vformat(" failed\n  ! mbedtls_ctr_drbg_seed returned an error %d.", ret));
 	return OK;
 }
 

core/debugger/engine_debugger.cpp

@@ -46,12 +46,12 @@ HashMap<String, EngineDebugger::CreatePeerFunc> EngineDebugger::protocols;
 void (*EngineDebugger::allow_focus_steal_fn)();
 
 void EngineDebugger::register_profiler(const StringName &p_name, const Profiler &p_func) {
-	ERR_FAIL_COND_MSG(profilers.has(p_name), "Profiler already registered: " + p_name);
+	ERR_FAIL_COND_MSG(profilers.has(p_name), vformat("Profiler already registered: '%s'.", p_name));
 	profilers.insert(p_name, p_func);
 }
 
 void EngineDebugger::unregister_profiler(const StringName &p_name) {
-	ERR_FAIL_COND_MSG(!profilers.has(p_name), "Profiler not registered: " + p_name);
+	ERR_FAIL_COND_MSG(!profilers.has(p_name), vformat("Profiler not registered: '%s'.", p_name));
 	Profiler &p = profilers[p_name];
 	if (p.active && p.toggle) {
 		p.toggle(p.data, false, Array());
@@ -61,22 +61,22 @@ void EngineDebugger::unregister_profiler(const StringName &p_name) {
 }
 
 void EngineDebugger::register_message_capture(const StringName &p_name, Capture p_func) {
-	ERR_FAIL_COND_MSG(captures.has(p_name), "Capture already registered: " + p_name);
+	ERR_FAIL_COND_MSG(captures.has(p_name), vformat("Capture already registered: '%s'.", p_name));
 	captures.insert(p_name, p_func);
 }
 
 void EngineDebugger::unregister_message_capture(const StringName &p_name) {
-	ERR_FAIL_COND_MSG(!captures.has(p_name), "Capture not registered: " + p_name);
+	ERR_FAIL_COND_MSG(!captures.has(p_name), vformat("Capture not registered: '%s'.", p_name));
 	captures.erase(p_name);
 }
 
 void EngineDebugger::register_uri_handler(const String &p_protocol, CreatePeerFunc p_func) {
-	ERR_FAIL_COND_MSG(protocols.has(p_protocol), "Protocol handler already registered: " + p_protocol);
+	ERR_FAIL_COND_MSG(protocols.has(p_protocol), vformat("Protocol handler already registered: '%s'.", p_protocol));
 	protocols.insert(p_protocol, p_func);
 }
 
 void EngineDebugger::profiler_enable(const StringName &p_name, bool p_enabled, const Array &p_opts) {
-	ERR_FAIL_COND_MSG(!profilers.has(p_name), "Can't change profiler state, no profiler: " + p_name);
+	ERR_FAIL_COND_MSG(!profilers.has(p_name), vformat("Can't change profiler state, no profiler: '%s'.", p_name));
 	Profiler &p = profilers[p_name];
 	if (p.toggle) {
 		p.toggle(p.data, p_enabled, p_opts);
@@ -85,7 +85,7 @@ void EngineDebugger::profiler_enable(const StringName &p_name, bool p_enabled, c
 }
 
 void EngineDebugger::profiler_add_frame_data(const StringName &p_name, const Array &p_data) {
-	ERR_FAIL_COND_MSG(!profilers.has(p_name), "Can't add frame data, no profiler: " + p_name);
+	ERR_FAIL_COND_MSG(!profilers.has(p_name), vformat("Can't add frame data, no profiler: '%s'.", p_name));
 	Profiler &p = profilers[p_name];
 	if (p.add) {
 		p.add(p.data, p_data);
@@ -106,7 +106,7 @@ bool EngineDebugger::has_capture(const StringName &p_name) {
 
 Error EngineDebugger::capture_parse(const StringName &p_name, const String &p_msg, const Array &p_args, bool &r_captured) {
 	r_captured = false;
-	ERR_FAIL_COND_V_MSG(!captures.has(p_name), ERR_UNCONFIGURED, "Capture not registered: " + p_name);
+	ERR_FAIL_COND_V_MSG(!captures.has(p_name), ERR_UNCONFIGURED, vformat("Capture not registered: '%s'.", p_name));
 	const Capture &cap = captures[p_name];
 	return cap.capture(cap.data, p_msg, p_args, r_captured);
 }
@@ -164,7 +164,7 @@ void EngineDebugger::initialize(const String &p_uri, bool p_skip_breakpoints, co
 	for (int i = 0; i < p_breakpoints.size(); i++) {
 		const String &bp = p_breakpoints[i];
 		int sp = bp.rfind(":");
-		ERR_CONTINUE_MSG(sp == -1, "Invalid breakpoint: '" + bp + "', expected file:line format.");
+		ERR_CONTINUE_MSG(sp == -1, vformat("Invalid breakpoint: '%s', expected file:line format.", bp));
 
 		singleton_script_debugger->insert_breakpoint(bp.substr(sp + 1, bp.length()).to_int(), bp.substr(0, sp));
 	}

core/debugger/remote_debugger.cpp

@@ -79,7 +79,7 @@ class RemoteDebugger::PerformanceProfiler : public EngineProfiler {
 		for (int i = 0; i < custom_monitor_names.size(); i++) {
 			Variant monitor_value = performance->call("get_custom_monitor", custom_monitor_names[i]);
 			if (!monitor_value.is_num()) {
-				ERR_PRINT("Value of custom monitor '" + String(custom_monitor_names[i]) + "' is not a number");
+				ERR_PRINT(vformat("Value of custom monitor '%s' is not a number.", String(custom_monitor_names[i])));
 				arr[i + max] = Variant();
 			} else {
 				arr[i + max] = monitor_value;
@@ -569,7 +569,7 @@ void RemoteDebugger::debug(bool p_can_continue, bool p_is_error_breakpoint) {
 				bool captured = false;
 				ERR_CONTINUE(_try_capture(command, data, captured) != OK);
 				if (!captured) {
-					WARN_PRINT("Unknown message received from debugger: " + command);
+					WARN_PRINT(vformat("Unknown message received from debugger: %s.", command));
 				}
 			}
 		} else {