Revert "add tracing v2 env var (#4465)"

This reverts commit b2f920e891.

langchain/callbacks/manager.py

@@ -32,11 +32,6 @@ openai_callback_var: ContextVar[Optional[OpenAICallbackHandler]] = ContextVar(
 tracing_callback_var: ContextVar[Optional[LangChainTracer]] = ContextVar(  # noqa: E501
     "tracing_callback", default=None
 )
-tracing_v2_callback_var: ContextVar[
-    Optional[LangChainTracerV2]
-] = ContextVar(  # noqa: E501
-    "tracing_callback_v2", default=None
-)
 
 
 @contextmanager
@@ -732,11 +727,6 @@ def _configure(
         or tracer is not None
         or os.environ.get("LANGCHAIN_HANDLER") is not None
     )
-
-    tracer_v2 = tracing_v2_callback_var.get()
-    tracing_v2_enabled_ = (
-        os.environ.get("LANGCHAIN_TRACING_V2") is not None or tracer_v2 is not None
-    )
     tracer_session = os.environ.get("LANGCHAIN_SESSION")
     if tracer_session is None:
         tracer_session = "default"
@@ -756,16 +746,6 @@ def _configure(
                 handler = LangChainTracer()
                 handler.load_session(tracer_session)
                 callback_manager.add_handler(handler, True)
-        if tracing_v2_enabled_ and not any(
-            isinstance(handler, LangChainTracerV2)
-            for handler in callback_manager.handlers
-        ):
-            if tracer_v2:
-                callback_manager.add_handler(tracer_v2, True)
-            else:
-                handler = LangChainTracerV2()
-                handler.load_session(tracer_session)
-                callback_manager.add_handler(handler, True)
         if open_ai is not None and not any(
             isinstance(handler, OpenAICallbackHandler)
             for handler in callback_manager.handlers

tests/integration_tests/callbacks/test_langchain_tracer.py

@@ -7,7 +7,6 @@ from aiohttp import ClientSession
 
 from langchain.agents import AgentType, initialize_agent, load_tools
 from langchain.callbacks import tracing_enabled
-from langchain.callbacks.manager import tracing_v2_enabled
 from langchain.llms import OpenAI
 
 questions = [
@@ -122,33 +121,3 @@ async def test_tracing_context_manager_async() -> None:
         await asyncio.gather(*tasks)
 
     await task
-
-
-@pytest.mark.asyncio
-async def test_tracing_v2_environment_variable() -> None:
-    os.environ["LANGCHAIN_TRACING_V2"] = "true"
-
-    aiosession = ClientSession()
-    llm = OpenAI(temperature=0)
-    async_tools = load_tools(["llm-math", "serpapi"], llm=llm, aiosession=aiosession)
-    agent = initialize_agent(
-        async_tools, llm, agent=AgentType.ZERO_SHOT_REACT_DESCRIPTION, verbose=True
-    )
-    tasks = [agent.arun(q) for q in questions[:3]]
-    await asyncio.gather(*tasks)
-    await aiosession.close()
-
-
-def test_tracing_v2_context_manager() -> None:
-    llm = OpenAI(temperature=0)
-    tools = load_tools(["llm-math", "serpapi"], llm=llm)
-    agent = initialize_agent(
-        tools, llm, agent=AgentType.ZERO_SHOT_REACT_DESCRIPTION, verbose=True
-    )
-    if "LANGCHAIN_TRACING_V2" in os.environ:
-        del os.environ["LANGCHAIN_TRACING_V2"]
-    with tracing_v2_enabled() as session:
-        assert session
-        agent.run(questions[0])  # this should be traced
-
-    agent.run(questions[0])  # this should not be traced