Bug#713886: grub-common: grub-mkconfig empties grub.cfg; old content not saved; system remains unbootable.

[Colin Watson]

On Mon, Jun 24, 2013 at 05:09:14PM +0200, Hans Putter wrote:
> Bug reproduced on a second PC, which is similiar to the first.
> 
> Please read the terminal-protocols in cfwatson.tar.gz
> in their chronological order:
> from cfwatson-1.txt (first) to cfwatson-8.txt (last).
> 
> The bug appeared when I used "apt-get dist-upgrade" with 68 (!)
> upgrades. It prevented me for a long time from actualizing my
> system.
> Instead of USB-sticks I use OS-clones on changeable HD's. Perhaps
> the execution marks got lost when copying my own grub.cfg from an
> old clone. Anyway, it would be useful to know whether this bug has
> been caused by the missing execution marks.

Yes, it is caused by the missing executable bits.

  chmod +x /etc/grub.d/[0-9]*
  update-grub

In general you must take great care to preserve executable bits when
copying bits of your operating system around.  Losing them can damage
all kinds of things.  If this happened to me I would investigate the bug
in my own processes with some urgency!

> If so, this should be documented in all relevant files.

It is already documented in the very first sentence of
/etc/grub.d/README (which you do not appear to have; you must have
deleted it for some reason).

  $ head -n2 /etc/grub.d/README
  
  All executable files in this directory are processed in shell expansion order.

Regards,

-- 
Colin Watson                                       [cjwatson at debian.org]