fix: initialize logger mutex

logging/include/logging/logging.h

@@ -145,7 +145,7 @@ class ASAP_LOGGING_API Logger final {
   std::shared_ptr<spdlog::logger> logger_;
   /// Synchronization lock used to synchronize logging over this logger from
   /// multiple threads.
-  std::unique_ptr<std::mutex> logger_mutex_{};
+  std::unique_ptr<std::mutex> logger_mutex_;
 
   /// Logger objects are created only by the Registry class.
   friend class Registry;

logging/src/logging.cpp

@@ -7,6 +7,8 @@
 #include "logging/logging.h"
 
 #include <iomanip> // std::setw
+#include <memory>
+#include <mutex>
 #include <sstream> // std::ostringstream
 #include <utility>
 
@@ -43,8 +45,9 @@ std::recursive_mutex Registry::loggers_mutex_; // NOLINT
 // Logger
 // ---------------------------------------------------------------------------
 
-Logger::Logger(const std::string &name, const spdlog::sink_ptr &sink) {
-  logger_ = std::make_shared<spdlog::logger>(name, sink);
+Logger::Logger(const std::string &name, const spdlog::sink_ptr &sink)
+    : logger_(std::make_shared<spdlog::logger>(name, sink)),
+      logger_mutex_(std::make_unique<std::mutex>()) {
   logger_->set_pattern(DEFAULT_LOG_FORMAT);
   logger_->set_level(spdlog::level::trace);
   // Ensure that critical errors, especially ASSERT/PANIC, get flushed