Fix gtkwave.py to be compatible with python 3.6

litex/build/sim/gtkwave.py

@@ -96,7 +96,7 @@ class GTKWSave:
         return prefix[:last_underscore + 1]
 
     def group(self,
-            signals: list[Signal],
+            signals: Sequence[Signal],
             group_name: str = None,
             alias: bool = True,
             closed: bool = True,

litex/tools/litex_sim.py

@@ -472,8 +472,6 @@ def main():
         if args.with_analyzer:
             soc.analyzer.export_csv(vns, "analyzer.csv")
         if args.gtkwave_savefile:
-            if sys.version_info[1] < 7:
-                raise OSError("--gtkwave-savefile option only supported for python 3.7+.")
             generate_gtkw_savefile(builder, vns, args.trace_fst)
 
 if __name__ == "__main__":