[Bug 1372673] Re: excessive debconf use when triggered
ljnelke
ljnelke at gmail.com
Tue Sep 23 16:53:12 UTC 2014
Sorry, I would test, but my screen since cracked and computer is useless.
Thanks for your help.
On Tue, Sep 23, 2014 at 12:40 PM, Chris J Arges <1372673 at bugs.launchpad.net>
wrote:
> Hello Colin, or anyone else affected,
>
> Accepted man-db into trusty-proposed. The package will build now and be
> available at http://launchpad.net/ubuntu/+source/man-db/2.6.7.1-1ubuntu1
> in a few hours, and then in the -proposed repository.
>
> Please help us by testing this new package. See
> https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to
> enable and use -proposed. Your feedback will aid us getting this update
> out to other Ubuntu users.
>
> If this package fixes the bug for you, please add a comment to this bug,
> mentioning the version of the package you tested, and change the tag
> from verification-needed to verification-done. If it does not fix the
> bug for you, please add a comment stating that, and change the tag to
> verification-failed. In either case, details of your testing will help
> us make a better decision.
>
> Further information regarding the verification process can be found at
> https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in
> advance!
>
> ** Changed in: man-db (Ubuntu Trusty)
> Status: In Progress => Fix Committed
>
> ** Tags added: verification-needed
>
> ** Changed in: man-db (Ubuntu Precise)
> Status: In Progress => Fix Committed
>
> --
> You received this bug notification because you are subscribed to a
> duplicate bug report (1198582).
> https://bugs.launchpad.net/bugs/1372673
>
> Title:
> excessive debconf use when triggered
>
> To manage notifications about this bug go to:
>
> https://bugs.launchpad.net/ubuntu/+source/man-db/+bug/1372673/+subscriptions
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You received this bug notification because you are a member of Ubuntu
Foundations Bugs, which is subscribed to man-db in Ubuntu.
https://bugs.launchpad.net/bugs/1372673
Title:
excessive debconf use when triggered
Status in “man-db” package in Ubuntu:
Fix Committed
Status in “man-db” source package in Lucid:
Fix Committed
Status in “man-db” source package in Precise:
Fix Committed
Status in “man-db” source package in Trusty:
Fix Committed
Status in “man-db” package in Debian:
Fix Released
Bug description:
SRU justification:
[Impact]
We see rather frequent hard-to-debug upgrade failures that amount to
man-db's trigger failing in some way that has nothing to do with the
mandb program itself, but rather in some kind of communication with
the package management frontend. Almost all the open bugs on Ubuntu
man-db come down to this in one way or another. The root cause is, I
believe, that it is not really safe to use debconf from a dpkg
trigger: while debconf itself behaves as if it were Essential, the
debconf protocol is often mediated by various frontends with less
stringent practices. It would certainly be a good idea to get man-
db's trigger out of the loop here, as dpkg tends to run it at the end
of an unpack phase when large numbers of packages are unconfigured,
which is pretty much the worst case for having this work properly.
In the past I've tried to investigate why debconf fails in these
situations. I've come to believe this is a wild goose chase, and that
the common case of ordinary postinsts sourcing the debconf confmodule
is much less likely to be a problem due to the nature of
unpack/configure sequencing; I admit that I don't have proof of this,
but having one fewer script using debconf is surely not going to make
things worse, and since lots of unpack runs pull the man-db trigger it
seems likely to improve things substantially.
The man-db trigger reads a single value from debconf to tell it
whether to automatically update the manual page database (used by
apropos and whatis). This is in an agreed location in debconf so that
such things as package builders can save time by suppressing the
database update. There is, however, no reason to read this value
every time the trigger is activated; we can just cache it under
/var/lib/man-db/ when man-db is configured and then do a much simpler
file-level test in the trigger. I should have thought of this years
ago.
To have the maximum benefit for upgraders, we should do what we can to
ensure that they have a fixed version of man-db installed before the
upgrade. I'd therefore like to apply this fix to all currently-
supported releases.
[Test Case]
I don't have a reliable reproduction scenario, but I have two
suggestions, which are in the sort of general vein of unit testing and
integration testing respectively:
* Install the new version of man-db and check that it causes /var/lib/man-db/auto-update to exist if and only if the debconf value for man-db/auto-update is true, and in turn that this still causes the database to be updated or not updated respectively when installing a package containing a manual page.
* After installing the new version of man-db, upgrade to the next supported or development series using the upgrade tool of your choice.
[Regression Potential]
Installing packages that contain manual pages and running system
upgrades should exercise this pretty thoroughly. Since in general
this weakens the constraints on achieving successful upgrades, the
main thing to watch out for would just be things like inverted logic
that might cause the database not to be updated when it should be or
vice versa.
Original report follows, imported from Debian bug
http://bugs.debian.org/579075:
Package: man-db
Version: 2.5.7-2
Severity: wishlist
I noticed that man-db starts debconf when triggered. Given how
often triggers run, I think that should be optimised. Ie, move
the $1 = triggered test above the confmodule sourcing.
-- System Information:
Debian Release: squeeze/sid
APT prefers unstable
APT policy: (500, 'unstable'), (500, 'stable')
Architecture: i386 (i686)
Kernel: Linux 2.6.32-3-686 (SMP w/2 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Versions of packages man-db depends on:
ii bsdmainutils 8.0.10 collection of more utilities from
ii debconf [debconf-2.0] 1.5.32 Debian configuration management sy
ii dpkg 1.15.7.1 Debian package management system
ii groff-base 1.20.1-9 GNU troff text-formatting system (
ii libc6 2.10.2-6 Embedded GNU C Library: Shared lib
ii libgdbm3 1.8.3-9 GNU dbm database routines (runtime
ii zlib1g 1:1.2.3.4.dfsg-3 compression library - runtime
man-db recommends no packages.
Versions of packages man-db suggests:
ii 5.0.386.0~svn20100423r45407-0u Chromium browser
ii 2.30.2-1 Intuitive GNOME web browser
pn <none> (no description available)
ii 3.5.9-2 Web browser based on Firefox
ii 436-1 pager program similar to more
ii 0.5.2-4 WWW browsable pager with excellent
-- debconf information excluded
--
see shy jo
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