Jetpack 4.2.1 : building v4l2loopback fails

Tried that on Xavier R32.3. Indeed, the module builds and install sucessfully, but when using v4l2sink in gstreamer, a cascade of faults related to v4l_enum_fmt can be seen in kernel messages at setup (although it seems working after).
This seems to happen with any v4l2loopback version from 0.11.0.
So for now I’d suggest to rather checkout v0.10.0 not having this problem:

...
root@nvidia-desktop:/usr/src# cd v4l2loopback/
root@nvidia-desktop:/usr/src/v4l2loopback# git checkout v0.10.0
root@nvidia-desktop:/usr/src/v4l2loopback# make
root@nvidia-desktop:/usr/src/v4l2loopback# make install
...

[EDIT: if you need some feature only available in v0.11 or v0.12, you would try this post.]