restore error message on restarting in a different mode

cylc/flow/scheduler.py

@@ -433,7 +433,7 @@ async def configure(self, params):
             if run_mode != og_run_mode:
                 raise InputError(
                     "This workflow was originally run in "
-                    f"{run_mode.value} mode:"
+                    f"{og_run_mode.value} mode:"
                     f" Will not restart in {run_mode.value} mode."
                 )
 

tests/integration/test_mode_on_restart.py

@@ -20,6 +20,7 @@
 
 from cylc.flow.exceptions import InputError
 from cylc.flow.scheduler import Scheduler
+from cylc.flow.run_modes import RunMode
 
 
 MODES = [('live'), ('simulation'), ('dummy')]
@@ -42,7 +43,7 @@ async def test_restart_mode(
     async with start(schd):
         if not mode_before:
             mode_before = 'live'
-        assert schd.get_run_mode() == mode_before
+        assert schd.get_run_mode().value == mode_before
 
     schd = scheduler(id_, run_mode=mode_after)
 
@@ -52,7 +53,7 @@ async def test_restart_mode(
     ):
         # Restarting in the same mode is fine.
         async with run(schd):
-            assert schd.get_run_mode() == mode_before
+            assert schd.get_run_mode().value == mode_before
     else:
         # Restarting in a new mode is not:
         errormsg = f'^This.*{mode_before} mode: Will.*{mode_after} mode.$'