guix: shepherd pid 1 holds /dev/console

On IRC chat we identified an issue related to linux SAK, which

is explained here

Following the check what processes will be SAK'ed:

~# ls -l /proc/[0-9]*/fd/* | grep console

lrwx------ 1 root root 64 Aug 24 21:22 /proc/1/fd/1 ->

/dev/console

lrwx------ 1 root root 64 Aug 24 21:22 /proc/1/fd/2 ->

/dev/console

l-wx------ 1 root root 64 Aug 24 21:22 /proc/578/fd/4 ->

/dev/console

lrwx------ 1 root root 64 Aug 24 21:22 /proc/593/fd/1 ->

/dev/console

lrwx------ 1 root root 64 Aug 24 21:22 /proc/593/fd/2 ->

/dev/console

lrwx------ 1 root root 64 Aug 24 20:03 /proc/705/fd/1 ->

/dev/console

lrwx------ 1 root root 64 Aug 24 20:03 /proc/705/fd/2 ->

/dev/console

lrwx------ 1 root root 64 Aug 24 21:22 /proc/909/fd/1 ->

/dev/console

lrwx------ 1 root root 64 Aug 24 21:22 /proc/909/fd/2 ->

/dev/console

As it is seen from above output, pid 1 which is shepherd holds

/dev/console

making linux SAK feature useless. When SAK command issued by

shortcut keys,

all above proceses gets killed including pid 1 which is shepherd,

causing

system to stall.