fix broadcast cancel error (#6952)

Author: oliver-sanders

changes.d/6952.fix.md

@@ -0,0 +1 @@
+Fixed `cylc broadcast` failing when cancelling `[events]` settings.

cylc/flow/cfgspec/workflow.py

@@ -2043,14 +2043,21 @@ def get_script_common_text(this: str, example: Optional[str] = None):
                 ''')
 
 
-def upg(cfg, descr):
+def upg(cfg, descr, for_cancel_broadcast=False):
     """Upgrade old workflow configuration.
 
     NOTE: We are silencing deprecation (and only deprecation) warnings
     when in Cylc 7 compat mode to help support Cylc 7/8 compatible workflows
     (which would loose Cylc 7 compatibility if users were to follow the
     warnings and upgrade the syntax).
 
+    Args:
+        for_cancel_broadcast:
+            If True, extra validation steps which inspect configuration values
+            will be skipped. This is used for "cylc broadcast --cancel" where
+            the values are not known.
+            See https://github.com/cylc/cylc-flow/issues/6950.
+
     """
     u = upgrader(cfg, descr)
 
@@ -2255,11 +2262,11 @@ def upg(cfg, descr):
     )
     u.upgrade()
 
-    upgrade_graph_section(cfg, descr)
-    upgrade_param_env_templates(cfg, descr)
-
-    warn_about_depr_platform(cfg)
-    warn_about_depr_event_handler_tmpl(cfg)
+    if not for_cancel_broadcast:
+        upgrade_graph_section(cfg, descr)
+        upgrade_param_env_templates(cfg, descr)
+        warn_about_depr_platform(cfg)
+        warn_about_depr_event_handler_tmpl(cfg)
 
     return u
 

cylc/flow/scripts/broadcast.py

@@ -167,7 +167,7 @@ def get_padding(settings, level=0, padding=0):
     return padding
 
 
-def get_rdict(left, right=None):
+def get_rdict(left, right=None, for_cancel_broadcast=False):
     """Check+transform left=right into a nested dict.
 
     left can be key, [key], [key1]key2, [key1][key2], [key1][key2]key3, etc.
@@ -193,7 +193,11 @@ def get_rdict(left, right=None):
             # item = right
             cur_dict[tail.strip()] = right
             tail = None
-    upg({'runtime': {'__MANY__': rdict}}, 'test')
+    upg(
+        {'runtime': {'__MANY__': rdict}},
+        'test',
+        for_cancel_broadcast=for_cancel_broadcast,
+    )
     # Perform validation, but don't coerce the original (deepcopy).
     cylc_config_validate(deepcopy(rdict), SPEC['runtime']['__MANY__'])
     return rdict
@@ -433,7 +437,7 @@ async def run(options: 'Values', workflow_id):
                 raise InputError(
                     "--cancel=[SEC]ITEM does not take a value")
             option_item = option_item.strip()
-            setting = get_rdict(option_item)
+            setting = get_rdict(option_item, for_cancel_broadcast=True)
             settings.append(setting)
         files_to_settings(settings, options.cancel_files, options.cancel)
         mutation_kwargs['variables'].update(