Each command class registers itself

src/commands/SetEnvelopeCommand.cpp

@@ -19,6 +19,7 @@
 #include "../Audacity.h"
 #include "SetEnvelopeCommand.h"
 
+#include "LoadCommands.h"
 #include "../WaveClip.h"
 #include "../WaveTrack.h"
 #include "../Envelope.h"
@@ -28,6 +29,9 @@
 const ComponentInterfaceSymbol SetEnvelopeCommand::Symbol
 { XO("Set Envelope") };
 
+namespace{ BuiltinCommandsModule::Registration< SetEnvelopeCommand > reg; }
+
+
 SetEnvelopeCommand::SetEnvelopeCommand()
 {
 }