Better exception type when sendfile is not available

Author: asvetlov

Lib/asyncio/base_events.py

@@ -659,12 +659,12 @@ async def sock_sendfile(self, sock, file, offset=0, count=None,
         try:
             return await self._sock_sendfile_native(sock, file,
                                                     offset, count)
-        except _SendfileNotAvailable:
+        except _SendfileNotAvailable as exc:
             if fallback:
                 return await self._sock_sendfile_fallback(sock, file,
                                                           offset, count)
             else:
-                raise
+                raise RuntimeError(exc.args[0]) from None
 
     async def _sock_sendfile_native(self, sock, file, offset, count):
         raise _SendfileNotAvailable("Fast sendfile is not available")

Lib/test/test_asyncio/test_base_events.py

@@ -1871,7 +1871,7 @@ def test__sock_sendfile_native_failure(self):
     def test_sock_sendfile_no_fallback(self):
         sock, proto = self.prepare()
 
-        with self.assertRaisesRegex(base_events._SendfileNotAvailable,
+        with self.assertRaisesRegex(RuntimeError,
                                     "Fast sendfile is not available"):
             self.run_loop(self.loop.sock_sendfile(sock, self.file,
                                                   fallback=False))