fix: guard log flush against OSError

app/logger.py

@@ -66,7 +66,10 @@ class LogInterceptor(io.TextIOWrapper):
         super().write(data)
 
     def flush(self):
-        super().flush()
+        try:
+            super().flush()
+        except OSError:
+            pass
         for cb in self._flush_callbacks:
             cb(self._logs_since_flush)
             self._logs_since_flush = []

tests-unit/app_test/logger_test.py

@@ -0,0 +1,26 @@
+import io
+
+from app.logger import LogInterceptor
+
+
+class FlushErrorBuffer(io.BytesIO):
+    def flush(self):
+        raise OSError(22, "Invalid argument")
+
+
+class FlushErrorStream:
+    buffer = FlushErrorBuffer()
+    encoding = "utf-8"
+    line_buffering = False
+
+
+def test_log_interceptor_flush_ignores_oserror_and_runs_callbacks():
+    interceptor = LogInterceptor(FlushErrorStream())
+    interceptor._logs_since_flush = [{"m": "message"}]
+    flushed_logs = []
+
+    interceptor.on_flush(lambda logs: flushed_logs.append(list(logs)))
+    interceptor.flush()
+
+    assert flushed_logs == [[{"m": "message"}]]
+    assert interceptor._logs_since_flush == []