[BUG] PromptFlow does not start trace of flow

[JoeyRoeters]

Describe the bug
I've upgraded to PF 1.17.1. Previously when starting a flow it would automaticly start a trace for the running flow. Now when executing a flow
it doesn't trace it anymore.

How To Reproduce the bug

1. run flow with 'pf flow test --flow {flow}

Expected behavior
it should start the pf service and start a trace for the running flow. It used to log in the console the url to the trace, this does not happen anymore as well.

Screenshots
n.a

Running Information(please complete the following information):

• Promptflow Package Version using: 1.17.1
• Operating System: MacOS 15.3 (24D60)
• Python Version using: 3.12.4

Additional context
The pf service is running, it did start the trace before the upgrade, after upgrading it's broken.

[philippeback]

Same issue. Went back to 1.16 where patching _trace.py got me traces to work (but token counting for llm nodes seems broken w a +dict message).

1.17 gives some OTL_... messages.

[liudmyla-b]

Here is what I found in CHANGELOG:

promptflow-tracing package

v1.17.1 (2025.1.13)

Others

• Promptflow Tracing feature is now disabled by default, with PF_DISABLE_TRACING set to true by default.

[Flowhill]

@liudmyla-b
How do we turn this on again?

[pback-ores]

@liudmyla-b How do we turn this on again?

set PF_DISABLE_TRACING=FALSE

then run the flow

[JoeyRoeters]

@liudmyla-b How do we turn this on again?

set PF_DISABLE_TRACING=FALSE

then run the flow

This does not seem to work for me on MacOS . I've run the flow with the given command, the command itself, and put the var inside my .zshrc but the trace is being collected.

[FabianSchurig]

@JoeyRoeters Could you try setting it in a devcontainer?

In this container it is working for me with the latest 1.17.2.

[Flowhill]

@liudmyla-b How do we turn this on again?

set PF_DISABLE_TRACING=FALSE

then run the flow

Is this in os.env or in the flow.dag.yaml?

[FabianSchurig]

@liudmyla-b How do we turn this on again?

set PF_DISABLE_TRACING=FALSE
then run the flow

Is this in os.env or in the flow.dag.yaml?

Both should work. Either

# flow.dag.yaml
environment_variables:
  PF_DISABLE_TRACING: "false"

or command line
export PF_DISABLE_TRACING=false

or Devcontainer

"containerEnv": {
		"POETRY_VIRTUALENVS_IN_PROJECT": "true",
		"PF_DISABLE_TRACING": "false"
	}

Can be closed?

[zcasanova]

Please update the main documentation, I spent so much time trying to figure out why this didn't work.

[JoeyRoeters]

@liudmyla-b How do we turn this on again?

set PF_DISABLE_TRACING=FALSE
then run the flow

Is this in os.env or in the flow.dag.yaml?

Both should work. Either

# flow.dag.yaml
environment_variables:
  PF_DISABLE_TRACING: "false"

or command line export PF_DISABLE_TRACING=false

or Devcontainer

"containerEnv": {
		"POETRY_VIRTUALENVS_IN_PROJECT": "true",
		"PF_DISABLE_TRACING": "false"
	}

Can be closed?

It did indeed work with specifying it within the flow.dag itself or adding it to the .env of the project. First i did try adding it to the zshrc of my own device, this did not work.

Indeed it should be specified better in the main documentation, also since it was build-in before the change.