ps reports Error: /proc must be mounted and also Segmentation fault?

[Shaul Karl]

I am just playing around with bf-common, not really knowing what I am doing. 
However, the following does not look right:

rakefet:/# ps
Error: /proc must be mounted
  To mount /proc at boot you need an /etc/fstab line like:
      /proc   /proc   proc    defaults
  In the meantime, mount /proc /proc -t proc
Segmentation fault
rakefet:/# 
 
I mean, why does it says Segmentation fault if it has the Error?
The Error is correct. I did not mount proc.