fix: shorten tracebacks on pipeline sync and exit

The details shown are only the communication bowels. So we go from:

    Traceback (most recent call last):
      File "trace.py", line 301, in <module>
        conn.execute("select pg_sleep(0.2)")
      File "/usr/lib/python3.8/contextlib.py", line 120, in __exit__
        next(self.gen)
      File "/home/piro/dev/psycopg3/psycopg/psycopg/connection.py", line 881, in pipeline
        yield pipeline
      File "/home/piro/dev/psycopg3/psycopg/psycopg/_pipeline.py", line 197, in __exit__
        self.sync()
      File "/home/piro/dev/psycopg3/psycopg/psycopg/_pipeline.py", line 183, in sync
        self._conn.wait(self._sync_gen())
      File "/home/piro/dev/psycopg3/psycopg/psycopg/connection.py", line 896, in wait
        return waiting.wait(gen, self.pgconn.socket, timeout=timeout)
      File "/home/piro/dev/psycopg3/psycopg/psycopg/waiting.py", line 237, in wait_epoll
        s = gen.send(ready)
      File "/home/piro/dev/psycopg3/psycopg/psycopg/_pipeline.py", line 92, in _sync_gen
        yield from self._communicate_gen()
      File "/home/piro/dev/psycopg3/psycopg/psycopg/_pipeline.py", line 105, in _communicate_gen
        self._process_results(queued, results)
      File "/home/piro/dev/psycopg3/psycopg/psycopg/_pipeline.py", line 149, in _process_results
        raise e.error_from_result(result, encoding=pgconn_encoding(self.pgconn))
    psycopg.errors.UndefinedColumn: column "foo" does not exist
    LINE 1: select foo
                   ^

to:

    Traceback (most recent call last):
      File "trace.py", line 301, in <module>
        conn.execute("select pg_sleep(0.2)")
      File "/usr/lib/python3.8/contextlib.py", line 120, in __exit__
        next(self.gen)
      File "/home/piro/dev/psycopg3/psycopg/psycopg/connection.py", line 881, in pipeline
        yield pipeline
      File "/home/piro/dev/psycopg3/psycopg/psycopg/_pipeline.py", line 205, in __exit__
        raise exc2.with_traceback(None)
    psycopg.errors.UndefinedColumn: column "foo" does not exist
    LINE 1: select foo
                   ^

which shows much more clearly that the traceback was raised at pipeline
block exit.

diff --git a/psycopg/psycopg/_pipeline.py b/psycopg/psycopg/_pipeline.py
index a62aa76b8a9b93909151070ae78331e3d009fb75..63bf765cbc6bd3a0d1a9e817ed4b0f36fde622ea 100644 (file)
--- a/psycopg/psycopg/_pipeline.py
+++ b/psycopg/psycopg/_pipeline.py
@@ -179,8 +179,11 @@ class Pipeline(BasePipeline):
         This is called when exiting the pipeline, but can be used for other
         purposes (e.g. in nested pipelines).
         """
-        with self._conn.lock:
-            self._conn.wait(self._sync_gen())
+        try:
+            with self._conn.lock:
+                self._conn.wait(self._sync_gen())
+        except e.Error as ex:
+            raise ex.with_traceback(None)
 
     def __enter__(self) -> "Pipeline":
         self._enter()
@@ -199,7 +202,7 @@ class Pipeline(BasePipeline):
             if exc_val:
                 logger.warning("error ignored syncing %r: %s", self, exc2)
             else:
-                raise
+                raise exc2.with_traceback(None)
         finally:
             try:
                 self._exit()
@@ -210,7 +213,7 @@ class Pipeline(BasePipeline):
                 if exc_val:
                     logger.warning("error ignored exiting %r: %s", self, exc2)
                 else:
-                    raise
+                    raise exc2.with_traceback(None)
 
 
 class AsyncPipeline(BasePipeline):
@@ -229,8 +232,11 @@ class AsyncPipeline(BasePipeline):
         This is called when exiting the pipeline, but can be used for other
         purposes (e.g. in nested pipelines).
         """
-        async with self._conn.lock:
-            await self._conn.wait(self._sync_gen())
+        try:
+            async with self._conn.lock:
+                await self._conn.wait(self._sync_gen())
+        except e.Error as ex:
+            raise ex.with_traceback(None)
 
     async def __aenter__(self) -> "AsyncPipeline":
         self._enter()
@@ -249,7 +255,7 @@ class AsyncPipeline(BasePipeline):
             if exc_val:
                 logger.warning("error ignored syncing %r: %s", self, exc2)
             else:
-                raise
+                raise exc2.with_traceback(None)
         finally:
             try:
                 self._exit()
@@ -257,4 +263,4 @@ class AsyncPipeline(BasePipeline):
                 if exc_val:
                     logger.warning("error ignored exiting %r: %s", self, exc2)
                 else:
-                    raise
+                    raise exc2.with_traceback(None)