By chance i discovered a kind of a compatibility problem:

Since i'm still struggling with my setup (kernel modules are missing,
machine tends to get very hot etc. pp.) i wanted to checkup which
graphic driver would be the best and i installed and tried to run
nvidia-detect - which gave me the following error:

Checking card: NVIDIA Corporation GF108M [GeForce GT 540M] (rev a1)

grep: /etc/debian_version: Datei oder Verzeichnis nicht gefunden
Uh oh. Failed to identify your Debian suite.

The script needs the Debian version to propose the correct driver, but
there is not such debian_version in etc.

Shouldn't devuan, as long as it uses in some way the debian
repositories, provide also the corrisponding debian_version file?