SC3.15 and above: ERROR: Found duplicate instance variable name

[prko]

Hello,

Thank you for your great quark package!
In the recent version of SC3.15-dev, I see the following errors (see supercollider/supercollider#7423 (comment)):

I should let you know it...

ERROR: Found duplicate instance variable name 'beat'
  in file '/Users/prko/Library/Application Support/SuperCollider/downloaded-quarks/Ctk/Ctk classes/Guido.sc'
  line 422 char 28:

  	var <>arrGuidoNotes, <>beat, <>spanner;
                              
  
-----------------------------------
WARNING: From version 3.16.0 onwards the preceding error will be a compilation failure, please fix the code before updating.

ERROR: Found duplicate instance variable name 'beat'
  in file '/Users/prko/Library/Application Support/SuperCollider/downloaded-quarks/Ctk/Ctk classes/LP.sc'
  line 1400 char 11:

  	var <>beat, <>tempo, <>string;
             
  	
-----------------------------------
WARNING: From version 3.16.0 onwards the preceding error will be a compilation failure, please fix the code before updating.

ERROR: Found duplicate instance variable name 'key'
  in file '/Users/prko/Library/Application Support/SuperCollider/downloaded-quarks/Ctk/Ctk classes/MusicXML.sc'
  line 1100 char 40:

  	var <measureNumber, <meter, <clef, <key, <firstBeat,/*<notes,*/<>divisions = 240, <key, <time,
                                          
  		<lastBeat, <numBeats, <>voiceNum = 1, <>voices;
-----------------------------------
WARNING: From version 3.16.0 onwards the preceding error will be a compilation failure, please fix the code before updating.

ERROR: Found duplicate instance variable name 'envbus'
  in file '/Users/prko/Library/Application Support/SuperCollider/downloaded-quarks/Ctk/Ctk classes/CTK.sc'
  line 2743 char 9:

  		<envbus, inc, <group, <>for = 0, <>by = 1, envsynth, envbus, playinit, notes,
           
  		score, <endtime, endtimeud, noFunc = false, eventDur;
-----------------------------------
WARNING: From version 3.16.0 onwards the preceding error will be a compilation failure, please fix the code before updating.