Bug#459199: Acknowledgement (grub-pc: locks up when upgrading)

[Robert Millan]

On Sun, Jan 06, 2008 at 11:21:18AM +1030, Arthur Marsh wrote:
> 
> 
> Robert Millan wrote, on 06/01/08 02:48:
> ...
> >>>You can use gdb to determine.  Try building a debug grub-mkdevicemap
> >>>(DEB_BUILD_OPTIONS=nostrip,noopt,debug), run it with gdb and interrupt it
> >>>where it has hung, then obtain a backtrace ("bt").
> 
> If you could give me the precise debuild or dpkg-buildpackage commands 
> to run after running
> 
> apt-get source grub2
> 
> I will at least know how to do this.

cd grub2-xxxxx
DEB_BUILD_OPTIONS=nostrip,noopt,debug dpkg-buildpackage -rfakeroot -b -uc 

> Even after scanning through /usr/share/doc/grub-pc including the 
> changelog and reading the last few months of the grub-devel mailing list 
> didn't tell me this. Should there be any manual pages or a README that 
> lists the executables and what they do?

Well yes, they should.  But they aren't :-)

Truly we need some help in writing documentation as you can see.

> My guess is that one of the upgrades in the previous week had been
> playing with device files, and since udev is active in my set-up, had
> created new device files in /dev/.static/dev but since udev hadn't been
> restarted by a reboot, something went wrong with the device scan.
> 
> The only files in /dev/.static/dev that looked like they might have been
> installed between my last reboot and the grub-pc upgrade were sg0 to
> sg16 - I have no idea what package would have created them, and they 
> don't end up under /dev outside of /dev/.static/dev after a reboot.

We need an actual diagnose of the problem.  A guess is only helpful as
a means to obtain that.  I have no problem with leaving this bug open if
you think you can reproduce it again, though.

> As Debian is  put together to reduce the need to reboot as much as 
> possible, your message about building a debug build will give the next 
> person who may encounter the problem and uses reportbug a clue on what 
> to do to better identify the problem.

My instructions are fairly generic really.  If not for this bug, at least
I hope they were useful to you on your next encounter with similar problems.

> Do you think that the grub-pc upgrade script and /usr/sbin/update-grub 
> shell script should indicate that they are running grub-mkdevicemap (and 
> when they have finished running grub-mkdevicemap) in case anyone else 
> hits this problem?

No.  Anyone who pretends to debug a shell script should know to read it
and see that for himself, tweak it for debugging if necessary, etc.  For
example, when I find a script that hangs, I usually insert a "set -x" in
its second line to make the script print all debugging information
automaticaly.

-- 
Robert Millan

<GPLv2> I know my rights; I want my phone call!
<DRM> What use is a phone call, if you are unable to speak?
(as seen on /.)