BUG: frontmatter is not rendered

[bsipocz]

Description

No frontdata is shown in the notebook. I have both project-wide (which I suppose won't show up anyway when looking at the individual notebooks in jupyter lab), but also notebook level frontmatter.
Here is all the metadata I have atm:

jupytext:
  text_representation:
    extension: .md
    format_name: myst
    format_version: 0.13
    jupytext_version: 1.17.3
kernelspec:
  display_name: Python 3 (ipykernel)
  language: python
  name: python3
authors:
  - name: Brigitta Sipőcz
  - name: IRSA Data Science Team
date: Tue, 30 Sep 2025
title: Random title to test if it shows

This could be a me issue as based on the docs I see that this should work out of the box, yet I don't see any frontmatter rendering at the top of the notebook.

I see a bunch of maybe relevant exceptions, but I believe I pip installed everything I needed, so if those should have been installed as well, so this may or may not be relevant here:

[I 2025-10-07 17:11:41.356 LabApp] Build is up to date
2025-10-07 17:11:44,680 - ServerApp - ERROR - Uncaught exception GET /api/nbconvert?1759871504543 (127.0.0.1)
HTTPServerRequest(protocol='http', host='localhost:8847', method='GET', uri='/api/nbconvert?1759871504543', version='HTTP/1.1', remote_ip='127.0.0.1')
Traceback (most recent call last):
  File "/Users/bsipocz/.pyenv/versions/3.12.1/lib/python3.12/site-packages/tornado/web.py", line 1790, in _execute
    result = await result
             ^^^^^^^^^^^^
  File "/Users/bsipocz/.pyenv/versions/3.12.1/lib/python3.12/site-packages/jupyter_server/auth/decorator.py", line 73, in inner
    return await out
           ^^^^^^^^^
  File "/Users/bsipocz/.pyenv/versions/3.12.1/lib/python3.12/site-packages/jupyter_server/services/nbconvert/handlers.py", line 41, in get
    exporters = await run_sync(base.get_export_names)
                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/bsipocz/.pyenv/versions/3.12.1/lib/python3.12/site-packages/anyio/to_thread.py", line 56, in run_sync
    return await get_async_backend().run_sync_in_worker_thread(
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/bsipocz/.pyenv/versions/3.12.1/lib/python3.12/site-packages/anyio/_backends/_asyncio.py", line 2144, in run_sync_in_worker_thread
    return await future
           ^^^^^^^^^^^^
  File "/Users/bsipocz/.pyenv/versions/3.12.1/lib/python3.12/site-packages/anyio/_backends/_asyncio.py", line 851, in run
    result = context.run(func, *args)
             ^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/bsipocz/.pyenv/versions/3.12.1/lib/python3.12/site-packages/nbconvert/exporters/base.py", line 145, in get_export_names
    e = get_exporter(exporter_name)(config=config)
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/bsipocz/.pyenv/versions/3.12.1/lib/python3.12/site-packages/nbconvert/exporters/base.py", line 106, in get_exporter
    exporter = items[0].load()
               ^^^^^^^^^^^^^^^
  File "/Users/bsipocz/.pyenv/versions/3.12.1/lib/python3.12/importlib/metadata/__init__.py", line 205, in load
    module = import_module(match.group('module'))
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/bsipocz/.pyenv/versions/3.12.1/lib/python3.12/importlib/__init__.py", line 90, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "<frozen importlib._bootstrap>", line 1387, in _gcd_import
  File "<frozen importlib._bootstrap>", line 1360, in _find_and_load
  File "<frozen importlib._bootstrap>", line 1310, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 488, in _call_with_frames_removed
  File "<frozen importlib._bootstrap>", line 1387, in _gcd_import
  File "<frozen importlib._bootstrap>", line 1360, in _find_and_load
  File "<frozen importlib._bootstrap>", line 1331, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 935, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 994, in exec_module
  File "<frozen importlib._bootstrap>", line 488, in _call_with_frames_removed
  File "/Users/bsipocz/.pyenv/versions/3.12.1/lib/python3.12/site-packages/jupyter_contrib_nbextensions/nbconvert_support/__init__.py", line 5, in <module>
    from .collapsible_headings import ExporterCollapsibleHeadings
  File "/Users/bsipocz/.pyenv/versions/3.12.1/lib/python3.12/site-packages/jupyter_contrib_nbextensions/nbconvert_support/collapsible_headings.py", line 6, in <module>
    from notebook.services.config import ConfigManager
ModuleNotFoundError: No module named 'notebook.services'
[W 2025-10-07 17:11:44.681 ServerApp] wrote error: 'Unhandled error'
    Traceback (most recent call last):
      File "/Users/bsipocz/.pyenv/versions/3.12.1/lib/python3.12/site-packages/tornado/web.py", line 1790, in _execute
        result = await result
                 ^^^^^^^^^^^^
      File "/Users/bsipocz/.pyenv/versions/3.12.1/lib/python3.12/site-packages/jupyter_server/auth/decorator.py", line 73, in inner
        return await out
               ^^^^^^^^^
      File "/Users/bsipocz/.pyenv/versions/3.12.1/lib/python3.12/site-packages/jupyter_server/services/nbconvert/handlers.py", line 41, in get
        exporters = await run_sync(base.get_export_names)
                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
      File "/Users/bsipocz/.pyenv/versions/3.12.1/lib/python3.12/site-packages/anyio/to_thread.py", line 56, in run_sync
        return await get_async_backend().run_sync_in_worker_thread(
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
      File "/Users/bsipocz/.pyenv/versions/3.12.1/lib/python3.12/site-packages/anyio/_backends/_asyncio.py", line 2144, in run_sync_in_worker_thread
        return await future
               ^^^^^^^^^^^^
      File "/Users/bsipocz/.pyenv/versions/3.12.1/lib/python3.12/site-packages/anyio/_backends/_asyncio.py", line 851, in run
        result = context.run(func, *args)
                 ^^^^^^^^^^^^^^^^^^^^^^^^
      File "/Users/bsipocz/.pyenv/versions/3.12.1/lib/python3.12/site-packages/nbconvert/exporters/base.py", line 145, in get_export_names
        e = get_exporter(exporter_name)(config=config)
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^
      File "/Users/bsipocz/.pyenv/versions/3.12.1/lib/python3.12/site-packages/nbconvert/exporters/base.py", line 106, in get_exporter
        exporter = items[0].load()
                   ^^^^^^^^^^^^^^^
      File "/Users/bsipocz/.pyenv/versions/3.12.1/lib/python3.12/importlib/metadata/__init__.py", line 205, in load
        module = import_module(match.group('module'))
                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
      File "/Users/bsipocz/.pyenv/versions/3.12.1/lib/python3.12/importlib/__init__.py", line 90, in import_module
        return _bootstrap._gcd_import(name[level:], package, level)
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
      File "<frozen importlib._bootstrap>", line 1387, in _gcd_import
      File "<frozen importlib._bootstrap>", line 1360, in _find_and_load
      File "<frozen importlib._bootstrap>", line 1310, in _find_and_load_unlocked
      File "<frozen importlib._bootstrap>", line 488, in _call_with_frames_removed
      File "<frozen importlib._bootstrap>", line 1387, in _gcd_import
      File "<frozen importlib._bootstrap>", line 1360, in _find_and_load
      File "<frozen importlib._bootstrap>", line 1331, in _find_and_load_unlocked
      File "<frozen importlib._bootstrap>", line 935, in _load_unlocked
      File "<frozen importlib._bootstrap_external>", line 994, in exec_module
      File "<frozen importlib._bootstrap>", line 488, in _call_with_frames_removed
      File "/Users/bsipocz/.pyenv/versions/3.12.1/lib/python3.12/site-packages/jupyter_contrib_nbextensions/nbconvert_support/__init__.py", line 5, in <module>
        from .collapsible_headings import ExporterCollapsibleHeadings
      File "/Users/bsipocz/.pyenv/versions/3.12.1/lib/python3.12/site-packages/jupyter_contrib_nbextensions/nbconvert_support/collapsible_headings.py", line 6, in <module>
        from notebook.services.config import ConfigManager
    ModuleNotFoundError: No module named 'notebook.services'
[E 2025-10-07 17:11:44.682 ServerApp] {
      "Host": "localhost:8847",
      "Accept": "*/*",
      "Referer": "http://localhost:8847/lab/tree/tutorials/spherex/spherex_psf.md",
      "User-Agent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:143.0) Gecko/20100101 Firefox/143.0"
    }
[E 2025-10-07 17:11:44.682 ServerApp] 500 GET /api/nbconvert?1759871504543 (8d0297a5c03346c0bf381c49ba0fc723@127.0.0.1) 97.86ms referer=http://localhost:8847/lab/tree/tutorials/spherex/spherex_psf.md
[I 2025-10-07 17:11:44.988 ServerApp] Kernel started: 52b00441-96b6-4735-b15e-a4cd474748b5
[I 2025-10-07 17:11:45.724 ServerApp] Connecting to kernel 52b00441-96b6-4735-b15e-a4cd474748b5.
[I 2025-10-07 17:11:45.728 ServerApp] Connecting to kernel 52b00441-96b6-4735-b15e-a4cd474748b5.
[I 2025-10-07 17:11:45.732 ServerApp] Connecting to kernel 52b00441-96b6-4735-b15e-a4cd474748b5.
[I 2025-10-07 17:13:45.122 ServerApp] Saving file at /tutorials/spherex/spherex_psf.md
[I 2025-10-07 17:13:45.123 ServerApp] Saving spherex_psf.md
⚠️  tutorials/spherex/spherex_psf.md:73 Legacy syntax used for link target, please prepend a '#' to your link url: "spherex-intro"
   The link target should be of the form `[](#target)`, including the `#` sign.
This may be deprecated in the future.
⚠️  tutorials/spherex/spherex_psf.md:73 Legacy syntax used for link target, please prepend a '#' to your link url: "spherex-cutouts"
   The link target should be of the form `[](#target)`, including the `#` sign.
This may be deprecated in the future.
📖 Built tutorials/spherex/spherex_psf.md in 152 ms.
💌 GET  /spherex-psf 200 - - 15.735 ms
💌 GET  /myst-theme.css 200 - - 3.644 ms
💌 GET  /favicon.ico - - - - ms

Proposed solution

I have no proposed solution

[bsipocz]

@agoose77 - I would feel this could/should be figured out before the release goes out. I have just checked and the example notebooks from this repo are not looking great either. Here are the screenshots:

ipynb works:

But the markdown doesn't. Note that the admonition renders as expected, so the plugin works partially.

[bsipocz]

Also note that jupyterlab created this diff as I opened up the notebooks, maybe it helps with some debugging:

diff --git a/examples/myst_tests.ipynb b/examples/myst_tests.ipynb
index ff3a9e8..28c6362 100644
--- a/examples/myst_tests.ipynb
+++ b/examples/myst_tests.ipynb
@@ -228,7 +228,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.10.6"
+   "version": "3.12.1"
   },
   "vscode": {
    "interpreter": {
diff --git a/examples/myst_tests.md b/examples/myst_tests.md
index c5c8cf6..e909b69 100644
--- a/examples/myst_tests.md
+++ b/examples/myst_tests.md
@@ -1,60 +1,32 @@
 ---
-title: Working with MyST Markdown
-subtitle: In JupyterLab
-doi: 10.14288/1.0362383
-license: CC-BY-4.0
-github: https://github.com/executablebooks/myst
-subject: Tutorial
-venue: Jupyter Journal
-biblio:
-  volume: '1'
-  issue: '1'
-authors:
-  - name: Rowan Cockett
-    email: rowan@curvenote.com
-    corresponding: true
-    orcid: 0000-0002-7859-8394
-    affiliations:
-      - Curvenote
-      - ExecutableBooks
-  - name: Steve Purves
-    affiliations:
-      - Curvenote
-      - ExecutableBooks
-math:
-  '\dobs': '\mathbf{d}_\text{obs}'
-  '\dpred': '\mathbf{d}_\text{pred}\left( #1 \right)'
-  '\mref': '\mathbf{m}_\text{ref}'
+jupyter:
+  jupytext:
+    text_representation:
+      extension: .md
+      format_name: pandoc
+      format_version: 2.9.2.1
+      jupytext_version: 1.17.3
+  kernelspec:
+    display_name: Python 3 (ipykernel)
+    language: python
+    name: python3
+  nbformat: 4
+  nbformat_minor: 5
 ---
 
-:::{note}
+::: {.cell .markdown}
 :class: dropdown
 This is MyST in a notebook rendered by `jupyterlab-myst`!!
-:::
 
-```{figure} https://source.unsplash.com/random/800x200?sunset
-:name: hello
-:width: 40%
-A nice sunset 🌅!!
-```
-
-```{figure} https://source.unsplash.com/random/800x200?beach,ocean
-:name: fig4
-:width: 40%
-Relaxing at the beach 🏖
-```
+`{figure} https://source.unsplash.com/random/800x200?sunset :name: hello :width: 40% A nice sunset 🌅!!`
 
-This chart shows an example of `using` an interval **selection**[^1] to filter the contents of an attached histogram, allowing the user to see the proportion of items in each category within the selection. See more in the [Altair Documentation](https://altair-viz.github.io/gallery/selection_histogram.html)
+`{figure} https://source.unsplash.com/random/800x200?beach,ocean :name: fig4 :width: 40% Relaxing at the beach 🏖`
 
-[^1]: Footnote text
+This chart shows an example of `using` an interval **selection**\[1\] to filter the contents of an attached histogram, allowing the user to see the proportion of items in each category within the selection. See more in the [Altair Documentation](https://altair-viz.github.io/gallery/selection_histogram.html)
 
-```{figure} https://source.unsplash.com/random/800x300?beach,ocean
-:name: fig3
-:width: 80%
-Relaxing at the beach
-```
+`{figure} https://source.unsplash.com/random/800x300?beach,ocean :name: fig3 :width: 80% Relaxing at the beach`
 
-```{math}
+``` {.{math}}
 :label: ok
 Ax=b
 ```
@@ -63,7 +35,7 @@ Ax=b
 
 [](#ok) [](#hello) [](#cross)
 
-```{warning}
+``` {.{warning}}
 :class: dropdown
 ok
 ```
@@ -72,25 +44,26 @@ The residual is the predicted data for the model, $\dpred{m}$, minus the observe
 
 For example, this [](#cross):
 
-```{math}
+``` {.{math}}
 :label: equation
 \sqrt{\frac{5}{2}}
 ```
 
 For example, this equation:
 
-```{math}
+``` {.{math}}
 :label: cross
 \mathbf{u} \times \mathbf{v}=\left|\begin{array}{ll}u_{2} & u_{3} \\ v_{2} & v_{3}\end{array}\right| \mathbf{i}+\left|\begin{array}{ll}u_{3} & u_{1} \\ v_{3} & v_{1}\end{array}\right| \mathbf{j}+\left|\begin{array}{ll}u_{1} & u_{2} \\ v_{1} & v_{2}\end{array}\right| \mathbf{k}
 ```
 
-<div><img src="https://source.unsplash.com/random/800x300?beach,ocean" width="100px"></div>
+`<img src="https://source.unsplash.com/random/800x300?beach,ocean" width="100px">`{=html}
 
+```{=html}
 <!-- just a comment! -->
-
+```
 ## Tabs
 
-````{tab-set}
+```` {.{tab-set}}
 ```{tab-item} Tab 1
 :sync: tab1
 Tab one can sync (see below)!
@@ -103,7 +76,7 @@ Tab two
 
 These tabs are set to sync:
 
-````{tab-set}
+```` {.{tab-set}}
 ```{tab-item} Tab 1 - Sync!
 :sync: tab1
 Tab one can sync!
@@ -118,29 +91,25 @@ Tab two
 
 ::::{grid} 1 1 2 3
 
-:::{grid-item-card}
 Text content ✏️
-^^^
+\^\^\^
 Structure books with text files and Jupyter Notebooks with minimal configuration.
-:::
 
-:::{grid-item-card}
 MyST Markdown ✨
-^^^
+\^\^\^
 Write MyST Markdown to create enriched documents with publication-quality features.
-:::
 
-:::{grid-item-card}
 Executable content 🔁
-^^^
+\^\^\^
 Execute notebook cells, store results, and insert outputs across pages.
-:::
+
 ::::
 
 ## Cards
 
-:::{card}
 MyST Markdown 🚀
-^^^
+\^\^\^
 Write content in JupyterLab!
-:::
+
+\[1\] Footnote text
+:::
\ No newline at end of file