Glyphs have components which are themselves components

[rbanffy]

com.google.fonts/check/glyf_nested_components
Check glyphs do not have components which are themselves components.
with gfonts_files/3270/3270-Regular.ttf

  Rationale:                                                                
  There have been bugs rendering variable fonts with nested components.     
  Additionally, some static fonts with nested components have been reported 
  to have rendering and printing issues.                                    
                                                                            
  For more info, see:                                                       
  * https://github.com/googlefonts/fontbakery/issues/2961                   
  * https://github.com/arrowtype/recursive/issues/412                       

 FAIL The following glyphs have components which themselves                 
      are component glyphs: * Ccaron * ccaron * Dcaron * Ecaron * ecaron *  
      Ncaron * ncaron * Ohungarumlaut * ohungarumlaut * Rcaron and 165 more.
      [code: found-nested-components]                                       


Result: FAIL