work around nuitka problem

engine/tempotrack.py

@@ -570,9 +570,20 @@ class TempoTrack(GraphTrackCC):
                         "graphType" : thisGraphItem.graphType,
                         "lilypondParameters" : thisGraphItem.lilypondParameters,
                         }
-                    if additionalData: #additional data is not for interpolated items
-                        exportDictItem.update(additionalData)
+
+                    #There was a problem with this in nuitka 0.6.10 with py 3.9.
+                    #The full dict was evaluating to False.
+                    #Working around this was trivial, but let's hope that was not just one example of countless problems.
+                    #if additionalData: #additional data is not for interpolated items
+                    #    print ("found additional for", id(thisGraphItem), additionalData)
+                    #    exportDictItem.update(additionalData)
+                    #else:
+                    #    print ("found NO additional for", id(thisGraphItem), additionalData)
+                    #    if "referenceTicks" in additionalData:
+                    #        print ("refTicks in additional!", additionalData)
+                    exportDictItem.update(additionalData)  #updating with an empty dict is ok as well.
                     result.append(exportDictItem)
+
                     typeString = "interpolated" #The next items in userItemAndInterpolatedItemsPositions are interpolated items. Reset once we leave the local forLoop.
 
             #Prepare data for the next block.