Export generates different sizes even though aspect was set to fixed value

[mrusme]

Describe the bug

I have a set of landscape photos that I cropped to 16:9. When exporting I set the long edge to 3840px. The exported files however randomly differ in width and height by several pixels. This doesn't seem reasonable, given that the source images are well over 6000px in width and the aspect was set to 3840, which should result in a consisten 3840x2160 size.

Steps to reproduce

1. Edit a handful of images, cropping them to 16:9
2. Select them all and export them with the size set to 3840px
3. Inspect the resulting files

Expected behavior

darktable should export files resulting in 3840x2160px

Logfile | Screenshot | Screencast

No response

Commit

No response

Where did you obtain darktable from?

distro packaging

darktable version

4.6.1

What OS are you using?

Linux

What is the version of your OS?

Gentoo

Describe your system?

Starlabs StarBook Mk VI AMD

Are you using OpenCL GPU in darktable?

Yes

If yes, what is the GPU card and driver?

AMD / ROCm

Please provide additional context if applicable. You can attach files too, but might need to rename to .txt or .zip

No response

[mrusme]

This is related to #3757 and #4412.

[zisoft]

Duplicate of #16638