Bug#592834: Grub messages during upgrade

[alsauser@pragmasoft.com]

On Thu, 09 Mar 2017 19:57:36 +0800 Steve M <steve.marr@icloud.com> wrote:
> Last couple of upgrades have seen similar results to the below:
> 
> Generating grub configuration file ...
> File descriptor 3 (pipe:[53933]) leaked on vgs invocation. Parent PID 9473: /usr/sbin/grub-probe
> File descriptor 3 (pipe:[53933]) leaked on vgs invocation. Parent PID 9473: /usr/sbin/grub-probe
> File descriptor 3 (pipe:[53933]) leaked on vgs invocation. Parent PID 9486: /usr/sbin/grub-probe
> File descriptor 3 (pipe:[53933]) leaked on vgs invocation. Parent PID 9486: /usr/sbin/grub-probe
> File descriptor 3 (pipe:[53933]) leaked on vgs invocation. Parent PID 9499: /usr/sbin/grub-probe
> File descriptor 3 (pipe:[53933]) leaked on vgs invocation. Parent PID 9499: /usr/sbin/grub-probe
> File descriptor 3 (pipe:[53933]) leaked on vgs invocation. Parent PID 9512: /usr/sbin/grub-probe
> File descriptor 3 (pipe:[53933]) leaked on vgs invocation. Parent PID 9512: /usr/sbin/grub-probe
> File descriptor 3 (pipe:[53933]) leaked on vgs invocation. Parent PID 9572: /usr/sbin/grub-probe
> File descriptor 3 (pipe:[53933]) leaked on vgs invocation. Parent PID 9572: /usr/sbin/grub-probe

I am experiencing the exact same messages.  Brand new Debian Stretch install, root file system installed on LVM volume.  Messages occur during subsequent apt-get install of mdadm package from "official" Debian 9.0.0 BluRay DVD (the apt-get install was performed immediately after a successful shutdown and reboot).  Same "pairs" of Parent PIDS: 1308,1308, 1338,1338, 1368,1368, 1398,1398, then 1563, etc.