/vagrant share folder not mounted after vagrant up

With the latest version of Vagrant, I made my own vagrant box with Linux Debian Bullseye and the latest version of SSH.
After vagrant up my virtualbox is runing but I can’t access to /vagrant. In the hypervisor configuration, the line for this directory appears and is the same as an other VM build with another box (Debian Buster). if I mount automatically the share folder with a click to the appropriate checkbox, all is OK. But during vagrant up the share folder operation is not completed. Below the error I received :

==> default: Preparing network interfaces based on configuration...
    default: Adapter 1: nat
==> default: Forwarding ports...
    default: 22 (guest) => 2222 (host) (adapter 1)
==> default: Booting VM...
==> default: Waiting for machine to boot. This may take a few minutes...
    default: SSH address:
    default: SSH username: vagrant
    default: SSH auth method: private key
==> default: Machine booted and ready!
==> default: Checking for guest additions in VM...
The following SSH command responded with a non-zero exit status.
Vagrant assumes that this means the command failed!

cat /proc/modules

Stdout from the command:

Stderr from the command:

My host’s OS is the Linux Debian Buster distribution version and my Guest’s OS platform is the Linux Debian Bullseye distribution.

Thanks for you replies :wink: to (try to) solve this trouble !

Hi Vincent

I have seen something similar, with an old (Ubuntu 12.04) guest
I’m not sure of the root cause, but it turned out to be the vbguest making trouble for me,
disabling it with

if Vagrant.has_plugin?(“vagrant-vbguest”)
config.vbguest.auto_update = false

solved the problem for me.