diff --git a/agent/bedrock_adapter.py b/agent/bedrock_adapter.py
index 26f0152516..a24513b026 100644
--- a/agent/bedrock_adapter.py
+++ b/agent/bedrock_adapter.py
@@ -205,7 +205,8 @@ def _stale_error_types() -> tuple:
         ("botocore.exceptions", ("ConnectionError", "HTTPClientError")),
         ("urllib3.exceptions", ("ProtocolError", "NewConnectionError", "ConnectionError")),
     ):
-        with suppress(ImportError):  # pragma: no cover — both present with boto3
+        # AttributeError too: ``from mod import Name`` raised ImportError for a missing name.
+        with suppress(ImportError, AttributeError):  # pragma: no cover — both present with boto3
             types += [getattr(importlib.import_module(module), name) for name in names]
     return tuple(types)
 
diff --git a/gateway/run_turn_runner.py b/gateway/run_turn_runner.py
index a7c0696cca..6735b49557 100644
--- a/gateway/run_turn_runner.py
+++ b/gateway/run_turn_runner.py
@@ -76,8 +76,11 @@ class TurnRunner:
             ctx._cleanup_msg_ids.append(str(result.message_id))
 
     def _track_future_cleanup_id(self, fut) -> None:
-        with suppress(Exception):
-            self._track_progress_result(fut.result())
+        try:
+            res = fut.result()
+        except Exception:
+            return
+        self._track_progress_result(res)
 
     # ── progress_callback (agent thread → progress queue) ───────────────────────────────────
 
diff --git a/tools/self_repo_guard.py b/tools/self_repo_guard.py
index a97bb2ffb0..35ab063966 100644
--- a/tools/self_repo_guard.py
+++ b/tools/self_repo_guard.py
@@ -70,10 +70,11 @@ class _ShellContext:  # one `(` / `$(` / backtick nesting level and its live quo
 
 def get_running_source_root() -> Path | None:
     """The source checkout backing this process, if there is one."""
-    with contextlib.suppress(OSError, RuntimeError):
+    try:
         root = Path(__file__).resolve().parent.parent
-        return root if (root / ".git").exists() else None
-    return None
+    except (OSError, RuntimeError):
+        return None
+    return root if (root / ".git").exists() else None
 
 
 def _resolve(path_str: str, base: Path) -> Path:
@@ -373,10 +374,11 @@ def _inspect_git(
         return None
     if alias.startswith("!"):  # shell alias: scan it as a command
         return _find_mutation(alias[1:], target, root, depth + 1)
-    with contextlib.suppress(ValueError):
+    try:
         alias_args = shlex.split(alias, posix=True)
-        return _inspect_git(executable, [*alias_args, *sub_args], target, {}, root, depth + 1)
-    return None
+    except ValueError:
+        return None
+    return _inspect_git(executable, [*alias_args, *sub_args], target, {}, root, depth + 1)
 
 
 def _inspect_github_cli(