+# Set other features.
+$g->set_selinux (1) if $selinux;
+$g->set_memsize ($memsize) if defined $memsize;
+
+# Set the kernel command line, which must include guestfs_rescue=1
+# (see appliance/init).
+my $str = "guestfs_rescue=1";
+$str .= " $append" if defined $append;
+$g->set_append ($str);
+
+# Run the appliance. This won't return until the user quits the
+# appliance.
+eval { $g->launch (); };
+
+# launch() expects guestfsd to start. However, virt-rescue doesn't run guestfsd,
+# so this will always fail with ECHILD when the appliance exits unexpectedly.
+die $@ unless $!{ECHILD};