ls: error: '.': No such file or directory

[pannous]

/sandbox$ mount /mount/point
Successfully mounted (...host path...)/opt at /mount/point.
/sandbox$ df -a
Filesystem          1k-blocks         Used    Available  Use% Mounted on       
wasi                        0            0            0     - /sandbox        
wasi                        0            0            0     - /mount/point    
/sandbox$ cd /mount/point
/mount/point$ ls
ls: error: '.': No such file or directory
Exit code: 1

[RReverser]

Hm, could be a permission issue, especially given the /opt in the end of your path (did you try mounting actual /opt? if so, I doubt the browser can access it).

What do you see in the console?