repo-architect: avoid unavailable model selection after catalog lookup

Co-authored-by: Steake <530040+Steake@users.noreply.github.com>

Author: Copilot

.github/workflows/repo-architect.yml

@@ -93,6 +93,7 @@ jobs:
           ]
           secondary = "google/gemini-3-pro"
           available = set()
+          catalog_ok = False
           try:
               req = urllib.request.Request(
                   "https://models.github.ai/catalog/models",
@@ -106,6 +107,7 @@ jobs:
                   payload = json.loads(resp.read().decode("utf-8"))
               models = payload.get("data", payload) if isinstance(payload, dict) else payload
               if isinstance(models, list):
+                  catalog_ok = True
                   for item in models:
                       if isinstance(item, dict):
                           model_id = item.get("id") or item.get("name") or item.get("model")
@@ -120,20 +122,30 @@ jobs:
                       return candidate
               return None
 
-          if available:
-              preferred = first_available(order)
-              if preferred is None:
-                  preferred = secondary if secondary in available else order[0]
+          def deterministic_available(exclude=None):
+              candidates = sorted(m for m in available if m != exclude)
+              return candidates[0] if candidates else None
+
+          if catalog_ok and available:
+              preferred = (
+                  first_available(order)
+                  or (secondary if secondary in available else None)
+                  or deterministic_available()
+              )
           else:
               preferred = order[0]
 
-          if secondary in available and secondary != preferred:
-              fallback = secondary
+          if catalog_ok and available:
+              if secondary in available and secondary != preferred:
+                  fallback = secondary
+              else:
+                  fallback = (
+                      first_available([c for c in order if c != preferred])
+                      or deterministic_available(exclude=preferred)
+                      or preferred
+                  )
           else:
-              fallback = (
-                  first_available([c for c in order if c != preferred])
-                  or (secondary if secondary in available else order[-1])
-              )
+              fallback = secondary
 
           if not isinstance(preferred, str) or not preferred:
               preferred = order[0]

repo_architect.py

@@ -1498,6 +1498,7 @@ def workflow_yaml(secret_env_names: Sequence[str], cron: str, github_model: Opti
           ]
           secondary = "google/gemini-3-pro"
           available = set()
+          catalog_ok = False
           try:
               req = urllib.request.Request(
                   "https://models.github.ai/catalog/models",
@@ -1511,6 +1512,7 @@ def workflow_yaml(secret_env_names: Sequence[str], cron: str, github_model: Opti
                   payload = json.loads(resp.read().decode("utf-8"))
               models = payload.get("data", payload) if isinstance(payload, dict) else payload
               if isinstance(models, list):
+                  catalog_ok = True
                   for item in models:
                       if isinstance(item, dict):
                           model_id = item.get("id") or item.get("name") or item.get("model")
@@ -1525,20 +1527,30 @@ def first_available(candidates):
                       return candidate
               return None
 
-          if available:
-              preferred = first_available(order)
-              if preferred is None:
-                  preferred = secondary if secondary in available else order[0]
+          def deterministic_available(exclude=None):
+              candidates = sorted(m for m in available if m != exclude)
+              return candidates[0] if candidates else None
+
+          if catalog_ok and available:
+              preferred = (
+                  first_available(order)
+                  or (secondary if secondary in available else None)
+                  or deterministic_available()
+              )
           else:
               preferred = order[0]
 
-          if secondary in available and secondary != preferred:
-              fallback = secondary
+          if catalog_ok and available:
+              if secondary in available and secondary != preferred:
+                  fallback = secondary
+              else:
+                  fallback = (
+                      first_available([c for c in order if c != preferred])
+                      or deterministic_available(exclude=preferred)
+                      or preferred
+                  )
           else:
-              fallback = (
-                  first_available([c for c in order if c != preferred])
-                  or (secondary if secondary in available else order[-1])
-              )
+              fallback = secondary
 
           if not isinstance(preferred, str) or not preferred:
               preferred = order[0]

tests/test_repo_architect.py

@@ -299,10 +299,15 @@ def test_workflow_yaml_resolves_models_via_catalog_and_keeps_blank_override_logi
         workflow = ra.workflow_yaml([], "17 * * * *", None)
         self.assertIn("Resolve GitHub Models configuration", workflow)
         self.assertIn("https://models.github.ai/catalog/models", workflow)
+        self.assertIn("catalog_ok = False", workflow)
         self.assertIn('"anthropic/claude-sonnet-4.6"', workflow)
         self.assertIn('"anthropic/claude-sonnet-4.5"', workflow)
         self.assertIn('"openai/gpt-4.1"', workflow)
         self.assertIn('secondary = "google/gemini-3-pro"', workflow)
+        self.assertIn("def deterministic_available(exclude=None):", workflow)
+        self.assertIn("or deterministic_available()", workflow)
+        self.assertIn("or deterministic_available(exclude=preferred)", workflow)
+        self.assertIn("or preferred", workflow)
         self.assertIn("REPO_ARCHITECT_PREFERRED_MODEL={preferred}", workflow)
         self.assertIn("REPO_ARCHITECT_FALLBACK_MODEL={fallback}", workflow)
         self.assertIn('if [ -n "$MODEL" ]; then EXTRA_ARGS="$EXTRA_ARGS --github-model $MODEL"; fi', workflow)