Thank you, Boris.
Ah, OK, I have guessed that input profile might be the solution.
But @anon41087856 talks there about linear spaces that are more close to humanvision (and XYZ space) like CIE xyY and CIE RGB.
And there is none of this space.
In LR or ACR or other soft, I usually use Adobe RGB or ProPhoto in order to get a wide color space with no clipping of colors taken by the camera, edit the image and transform them to sRGB (and fight against color clipping or conversions) when I want to save it as a jpeg to the web.
The logical approach in darktable (in the move from CIE LAB to a linear space) seems to use CIE xyY as working space for the editions and fight color conversions during the export.
But there is no such working space.
By default it seems that linear Rec2019 is selected (with my canon camera, I don’t know whether that matters).
I don’t know that color space, it seems to be video related, and seems like a strange selection to me.
Yes, there seems that there are modules working in LAB and others in linear space.
But, does that mean that each module converts the pipeline data to its own internal working space and then back to the darktable working space?
Or does the module assume that the working space is the correct one and blindly applies its correction even if you are using a linear working space?
For modules that are linear, will the results be the same if you are working in any linear space?
What happens if you are using AdobeRGB or sRGB that are gamma compensated?
Do they work the same by converting to a linear data before their calculations?