Cuttlefish and userdata partition image

[Christian Gagneraud]

Hi all,

I'm trying to boot up cuttlefish with a premade userdata image (loaded
with instrumentation, unit and tradefed tests).
I'm on Android 11, and I've noticed that launch_cvd doesn't pass on
the --data_image to the cvd assembler, it keeps picking up
userdata.img from --system_image_dir.
Mounting the default userdata.img, it looks empty to me.
When I replace it with my own F2FS image, cuttlefish doesn't boot. :(

Has anyone experienced similar problems with cuttlefish? Any hints or
point out on how to deal with usedata images would be helpful.

Thanks,
Chris