fix missing lilypond variable. also protect export from crashing everything§

engine/api.py

@@ -2493,13 +2493,23 @@ def midiRelativeChannelReset():
 #Lilypond
 
 def lilypondText(text):
-    insertItem(items.LilypondText(text))
+    try:
+        insertItem(items.LilypondText(text))
+    except Exception as err:
+        logger.error(err)
 
 def exportLilypond(absoluteFilePath):
-    lilypond.saveAsLilypond(session.data, absoluteFilePath)
+    try:
+        lilypond.saveAsLilypond(session.data, absoluteFilePath)
+    except Exception as err:
+        logger.error(err)
 
 def showPDF():
-    lilypond.saveAsLilypondPDF(session.data, openPDF = True)
+    try:
+        lilypond.saveAsLilypondPDF(session.data, openPDF = True)
+    except Exception as err:
+        logger.error(err)
+
 
 def getLilypondBarlineList()->Iterable[Tuple[str, Callable]]:
     """Return a list of very similar functions for a convenience menu in a GUI.

engine/track.py

@@ -818,9 +818,8 @@ class Track(object):
         """Called by score.lilypond(), returns a string.
 
         We carry a dict around to hold lilypond on/off markers like tuplets
-        that need to set as ranges.
-
-
+        that need to set as ranges. This dict begins here. Each track
+        gets its own.
         """
         for item in self.blocks[0].data[:4]:
             if type(item) is MetricalInstruction:
@@ -829,10 +828,11 @@ class Track(object):
         else:
             timeSig = "\\once \\override Staff.TimeSignature   #'stencil = ##f \\cadenzaOn "
 
-        upbeatLy = "\\partial {} ".format(Duration.createByGuessing(self.upbeatInTicks).lilypond()) if self.upbeatInTicks else ""
-
         carryLilypondRanges = {} #handed from item to item for ranges such as tuplets. Can act like a stack or simply remember stuff.
 
+        upbeatLy = "\\partial {} ".format(Duration.createByGuessing(self.upbeatInTicks).lilypond(carryLilypondRanges)) if self.upbeatInTicks else ""
+
+
         data = " ".join(block.lilypond(carryLilypondRanges) for block in self.blocks)
         if data:
             return timeSig + upbeatLy + data