a lot of bug potential here

src/fsfw_hal/linux/UnixFileGuard.cpp

@@ -8,7 +8,7 @@
 
 UnixFileGuard::UnixFileGuard(const std::string& device, int& fileDescriptor, int flags,
                              std::string diagnosticPrefix)
-    : cachedFd(fileDescriptor) {
+    : fdRef(fileDescriptor) {
   fileDescriptor = open(device.c_str(), flags);
   if (fileDescriptor < 0) {
 #if FSFW_VERBOSE_LEVEL >= 1
@@ -24,6 +24,6 @@ UnixFileGuard::UnixFileGuard(const std::string& device, int& fileDescriptor, int
   }
 }
 
-UnixFileGuard::~UnixFileGuard() { close(cachedFd); }
+UnixFileGuard::~UnixFileGuard() { close(fdRef); }
 
 ReturnValue_t UnixFileGuard::getOpenResult() const { return openStatus; }

src/fsfw_hal/linux/UnixFileGuard.h

@@ -31,7 +31,7 @@ class UnixFileGuard {
   ReturnValue_t getOpenResult() const;
 
  private:
-  int cachedFd = 0;
+  int& fdRef;
   ReturnValue_t openStatus = returnvalue::OK;
 };