So, uh, if you've been running the alpha builds of the Codex CLI lately,
you-you-you probably noticed things got a little, well, messy if you were trying to
debug complex multi-agent runs.
Oh, and before I forget, massive thanks to Jellypod to help make this daily show a
reality.
But yeah, we-we're talking about rollout tracing, which is that opt-in diagnostic
system that basically logs every raw event locally so you can compile them offline.
And in the recent zero-dot-one-forty-three-dot-zero alpha builds,
if you tried to run the codex debug trace-reduce command on those logs,
it would just completely crash.
Like, boom, stack trace, game over.
Yeah, it was-it was pretty spectacular.
And the culprit was actually this tiny, seemingly harmless metadata passthrough
field, specifically turn_id inside the model-visible tool calls.
The compiler, uh, it-it just didn't know how to handle it when it was trying to hash
and compare the JSON bodies.
Right, because the trace-reduce compiler is trying to look at these massive JSON
payloads and dedup or group them by hashing the body.
But when you have fluctuating metadata like turn_id injected into the tool calls,
the hashes don't match even if the semantic tool call is identical.
The compiler was just choking on that variance.
Exactly.
So, the fix they just shipped in the latest zero-dot-one-forty-three-dot-zero-alpha
releases is actually pretty straightforward but crucial.
They, uh, they literally just strip out those non-identity metadata fields right
before the hashing and comparison stage.
So now, the compiler ignores turn_id and other transient fields,
hashes the actual structural JSON, and boom, your offline diagnostic compilation is
stable again.
It's honestly a lifesaver if you're dealing with deep nested loops where agents are
calling tools back and forth.
If you can't reduce those traces, you're basically staring at a multi-gigabyte text
file of raw JSON events, which is...
yeah, not fun.
Oh, absolutely.
Staring at raw JSON is-is a special kind of developer purgatory.
But-but here's the thing, setting this up is actually a bit hidden.
To even turn on rollout tracing, you have to set this specific environment variable:
CODEX_ROLLOUT_TRACE_ROOT and point it to a local directory.
And once the raw events write there, that's when you run that hidden CLI tool,
codex debug trace-reduce --input --output to
compile it all into a readable graph.
Wait, so it's writing everything to disk?
Like, everything-everything?
Yes, and that is a massive security gotcha.
Because rollout traces write *everything*-we're talking raw source code,
active API credentials that might be in your environment, and raw prompts-straight
to your local disk in plain text.
If you don't add that trace directory to your global .gitignore,
you are one lazy git add .
away from pushing your entire local secret key vault to a public repo.
Oh, yikes.
Yeah, that-that is a recipe for an absolute disaster.
Seriously, if you are listening to this right now and using the alpha,
go add your trace root directory to your .gitignore immediately.
Like, pause the podcast and do it.
Seriously, do it now.
And-and while you're messing with the alpha channel, there's another really weird UX
bug in the terminal user interface, the TUI.
If you use the /feedback command to report an issue, and you type your feedback
right after the command on the same line...
it-it doesn't actually go to the feedback pipeline.
Wait, what?
Where does it go then?
It gets misrouted.
The CLI treats any trailing arguments after /feedback as a standard chat prompt.
So instead of filing a bug report, you're literally just sending your feedback text
to the LLM agent as your next chat turn.
It's-it's wild.
That is...
wow.
So the agent is just going to reply to you complaining about the bug,
instead of actually filing it.
Okay, so the workaround there is to just type /feedback, hit enter,
and wait for the dedicated prompt.
Got it.
Well, that's it for our quick look at the Codex diagnostics.
Keep those trace roots out of Git, and we'll catch you next time.