Does this make the build action work?

trunk-recorder/gr_blocks/transmission_sink.h

@@ -34,7 +34,51 @@
 #include <gnuradio/sync_block.h>
 
 class Call;
-struct Transmission;
+struct Transmission {
+    long source;
+    time_t start_time;
+    time_t stop_time;
+    long sample_count;
+    long spike_count;
+    long error_count;
+    double length;
+    char filename[255];
+
+    // Add default constructor
+    Transmission() : source(0), start_time(0), stop_time(0), 
+                    sample_count(0), spike_count(0), error_count(0), 
+                    length(0.0) {
+        filename[0] = '\0';
+    }
+
+    // Add copy constructor
+    Transmission(const Transmission& other) {
+        source = other.source;
+        start_time = other.start_time;
+        stop_time = other.stop_time;
+        sample_count = other.sample_count;
+        spike_count = other.spike_count;
+        error_count = other.error_count;
+        length = other.length;
+        std::strncpy(filename, other.filename, sizeof(filename));
+    }
+
+    // Add assignment operator
+    Transmission& operator=(const Transmission& other) {
+        if (this != &other) {
+            source = other.source;
+            start_time = other.start_time;
+            stop_time = other.stop_time;
+            sample_count = other.sample_count;
+            spike_count = other.spike_count;
+            error_count = other.error_count;
+            length = other.length;
+            std::strncpy(filename, other.filename, sizeof(filename));
+        }
+        return *this;
+    }
+};
+
 namespace gr {
 namespace blocks {