python: QUARTO_EXECUTE_INFO only accessible upon the very first render of the qmd notebook in a given venv

[paniterka]

I have:

• searched the issue tracker for similar issues
• installed the latest version of Quarto CLI
• formatted my issue following the Bug Reports guide

Bug description

Hi, I am looking for a way to conditionally execute a chunk of Python code, based on the output format of the rendered document. I would like to use the QUARTO_EXECUTE_INFO environmental variable for this. However, I run into the problem that the QUARTO_EXECUTE_INFO is only accessible upon the very first render of the qmd file. Upon every re-render of the same file (changed or unchanged), I am not able to read the json anymore. The only reproducible way I found to get it back to work is to change the python kernel used to render the qmd file (i.e. replace jupyter: python3 with jupyter: myenv for example). Even then, it only works upon the very first execution and upon each subsequent re-render the json file cannot be accessed.

Steps to reproduce

---
title: 'Test'
date: last-modified
published-title: Last updated on
execute:
  freeze: true
  echo: false
  warning: false
jupyter: python3

---


```{python}
import os 
import json
for i in ["QUARTO_DOCUMENT_PATH", "QUARTO_EXECUTE_INFO", "QUARTO_PROJECT_ROOT"]:
	print(f"{i}: {os.environ[i]}")
print('try to read in the json')
try:
	with open(os.environ["QUARTO_EXECUTE_INFO"]) as f:
		info = json.load(f)
	# Access format information
	print(f'json read in, output format is {info["format"]["identifier"]["target-format"]}')
except: 
	print('json not accessible')

```

To reproduce: run quarto render env_test.qmd --to html a few times in a row and inspect the result file each time

Actual behavior

on the very first render in a given kernel, the json to which QUARTO_EXECUTE_INFO is pointing to can be accessed, and on every next re-render it is not accessible.

Expected behavior

QUARTO_EXECUTE_INFO json should be accessible upon every re-render

Your environment

IDE: Notepad++
Windows 11

Quarto check output

> quarto check

Quarto 1.8.25
[>] Checking environment information...
      Quarto cache location: C:\Users\t\AppData\Local\quarto
[>] Checking versions of quarto binary dependencies...
      Pandoc version 3.6.3: OK
      Dart Sass version 1.87.0: OK
      Deno version 2.3.1: OK
      Typst version 0.13.0: OK
[>] Checking versions of quarto dependencies......OK
[>] Checking Quarto installation......OK
      Version: 1.8.25
      Path: C:\Users\t\AppData\Local\Programs\Quarto\bin
      CodePage: 1252

[>] Checking tools....................OK
      TinyTeX: v2025.10
      Chromium: (not installed)

[>] Checking LaTeX....................OK
      Using: TinyTex
      Path: C:\Users\t\AppData\Roaming\TinyTeX\bin\windows\
      Version: 2025

[>] Checking Chrome Headless....................OK
      Using: Chrome found on system
      Path: C:\Program Files\Google\Chrome\Application\chrome.exe
      Source: Windows Registry

[>] Checking basic markdown render....OK

[>] Checking Python 3 installation....OK
      Version: 3.12.12 (Conda)
      Path: C:/APPS/Anaconda3/envs/tobireports/python.exe
      Jupyter: 5.9.1
      Kernels: python3, duckdb_env, tobireports

[>] Checking Jupyter engine render....OK

[>] Checking R installation...........OK
      Version: 4.1.2
      Path: C:/Users/t/Documents/R/R-4.1.2
      LibPaths:
        - C:/Users/t/Documents/R/R-4.1.2/library
      knitr: 1.37
      rmarkdown: 2.11

[>] Checking Knitr engine render......OK

> jupyter --version

Selected Jupyter core packages...
IPython          : 9.6.0
ipykernel        : 7.0.1
ipywidgets       : not installed
jupyter_client   : 8.6.3
jupyter_core     : 5.9.1
jupyter_server   : not installed
jupyterlab       : not installed
nbclient         : 0.10.2
nbconvert        : not installed
nbformat         : 5.10.4
notebook         : not installed
qtconsole        : not installed
traitlets        : 5.14.3

[cscheid]

Thanks for the report. Can you check if the problem persists if you use '--no-execute-daemon'? I want to confirm that this is the cause.

[paniterka]

Thanks a lot for a quick answer!
quarto render env_test.qmd --to html --no-execute-daemon fixes the problem and I am able to access the json upon each render.

[dsliwka]

There is a related (or maybe the same) issue: The QUARTO_EXECUTE_INFO file often does not exist during execution on Windows

Environment: Windows, Quarto 1.8.26

Minimal reproduction

---
format: html
---

```{python}
import os
from pathlib import Path

info_path = os.environ.get("QUARTO_EXECUTE_INFO")
print(f"Info path: {info_path}")
print(f"Exists: {Path(info_path).exists()}")
```

When rendering from the terminal with quarto render test.ipynb --execute it gives:

Info path: C:\Users...\AppData\Local\Temp\quarto-session.........
Exists: False

Note: Works correctly in VS Code Preview:

Info path: C:\Users...\AppData\Local\Temp\quarto-session.........
Exists: True

The issue is also resolved when using --no-execute-daemon. But is this intended behavior (consistent access to QUARTO_EXECUTE_INFO would be extremely useful in any python package generating format specific output)?