openai/codex · error · anyhow::Error

code cell start referenced unknown thread {thread_id}

Error message

code cell start referenced unknown thread {thread_id}

What it means

Error "code cell start referenced unknown thread {thread_id}" thrown in openai/codex.

Source

Thrown at codex-rs/rollout-trace/src/reducer/code_cell.rs:642

        &self,
        thread_id: &str,
        requester: RawToolCallRequester,
    ) -> Result<ToolCallRequester> {
        match requester {
            RawToolCallRequester::Model => Ok(ToolCallRequester::Model),
            RawToolCallRequester::CodeCell { runtime_cell_id } => Ok(ToolCallRequester::CodeCell {
                code_cell_id: self.code_cell_id_for_runtime_cell_id(
                    thread_id,
                    &runtime_cell_id,
                    "code-mode nested tool",
                )?,
            }),
        }
    }

    fn validate_code_cell_turn(&self, thread_id: &str, codex_turn_id: &str) -> Result<()> {
        if !self.rollout.threads.contains_key(thread_id) {
            bail!("code cell start referenced unknown thread {thread_id}");
        }
        let Some(turn) = self.rollout.codex_turns.get(codex_turn_id) else {
            bail!("code cell start referenced unknown Codex turn {codex_turn_id}");
        };
        if turn.thread_id != thread_id {
            bail!(
                "code cell start used thread {thread_id}, but Codex turn {codex_turn_id} belongs \
                 to {}",
                turn.thread_id
            );
        }
        Ok(())
    }

    fn model_visible_code_cell_item_ids(
        &self,
        thread_id: &str,
        call_id: &str,

View on GitHub (pinned to 339751715c)

When it happens

Trigger: Thrown at codex-rs/rollout-trace/src/reducer/code_cell.rs:642 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of openai/codex@339751715c (2026-08-25). Data as JSON: /api/errors/2efb69538aa4d0f2. Report an issue: GitHub.