Sharing host file systems with a VM

[Ludovic Courtès]

‘guix system vm’ can now be told to share more file systems with the
host, in addition to /gnu/store:

     Additional file systems can be shared between the host and the VM
     using the ‘--share’ and ‘--expose’ command-line options: the former
     specifies a directory to be shared with write access, while the
     latter provides read-only access to the shared directory.

     The example below creates a VM in which the user’s home directory
     is accessible read-only, and where the ‘/exchange’ directory is a
     read-write mapping of the host’s ‘$HOME/tmp’:

          guix system vm my-config.scm \
             --expose=$HOME --share=$HOME/tmp=/exchange

Thanks David for giving me an incentive to work on this.  ;-)

Ludo’.