Widget not displaying in marimo 0.15.3 or newer #6499
Description
Describe the bug
Hi,
I noticed that my widget stopped working in marimo recently. Tracked it down to marimo 0.15.3 as the first version where it breaks. At first I thought it's something I changed in the widget recently, but the widget renders correctly in with marimo v0.15.2, jupyter, and colab. Also still happens with marimo 0.16.1.
Minimal reproducible example:
https://gist.github.com/dvdkouril/27db97e757071abc1cf67c6b5f6ca718
uvx [email protected] edit https://gist.githubusercontent.com/dvdkouril/27db97e757071abc1cf67c6b5f6ca718/raw/30a30667b393b82d9d617819089ce1870cf913fc/uchimata-example.py
uvx [email protected] edit https://gist.githubusercontent.com/dvdkouril/27db97e757071abc1cf67c6b5f6ca718/raw/30a30667b393b82d9d617819089ce1870cf913fc/uchimata-example.py
Will you submit a PR?
- Yes
Environment
{
"marimo": "0.16.1",
"editable": false,
"location": "/Users/davidkouril/projects/dvdkouril/brain-lifespan-3d-chromatin/.venv/lib/python3.13/site-packages/marimo",
"OS": "Darwin",
"OS Version": "24.6.0",
"Processor": "arm",
"Python Version": "3.13.0",
"Locale": "en_US",
"Binaries": {
"Browser": "140.0.7339.186",
"Node": "v22.17.1"
},
"Dependencies": {
"click": "8.3.0",
"docutils": "0.22.2",
"itsdangerous": "2.2.0",
"jedi": "0.19.2",
"markdown": "3.9",
"narwhals": "2.5.0",
"packaging": "25.0",
"psutil": "7.1.0",
"pygments": "2.19.2",
"pymdown-extensions": "10.16.1",
"pyyaml": "6.0.2",
"starlette": "0.48.0",
"tomlkit": "0.13.3",
"typing-extensions": "4.15.0",
"uvicorn": "0.35.0",
"websockets": "15.0.1"
},
"Optional Dependencies": {
"anywidget": "0.9.18",
"duckdb": "1.4.0",
"nbformat": "5.10.4",
"pandas": "2.3.2",
"pyarrow": "21.0.0",
"loro": "1.6.0"
},
"Experimental Flags": {}
}```
</details>
### Code to reproduce
https://gist.github.com/dvdkouril/27db97e757071abc1cf67c6b5f6ca718