New code in dependent cells is not used

[jojozie]

Hi,

while testing around with the reactive execution of Marimo I got stuck with the following behavior:

My notebook has two cells. Cell 2 is dependent of cell 1 as it uses a variable declared in cell 1. Now I change the code in both cells without executing it. Both cells get stale. Now I execute the first cell, expecting the second cell to be run with my edited code. But in fact, marimo executes the second cell with the old code.

This seems very unintuitive to me. Is this intentional behavior?

Here is a screencast of the example and the python file of the marimo app.

Screen.Recording.2025-11-05.at.16.09.05.mov

import marimo

__generated_with = "0.17.6"
app = marimo.App(width="medium")


@app.cell
def _():
    a = 0
    return (a,)


@app.cell
def _(a):
    b = a + 0
    return


if __name__ == "__main__":
    app.run()

[mscolnick]

@jojozie yes this is intentional (we don't know that you are done editing that cell and it could be expensive). in order to run all stale cells here, you can hit the run button in the bottom right corner.

[stephenlf]

I habitually use CTRL SHIFT R to run stale cells. It will run all stale cells.