On Sun, 14 Mar 2010 20:54:18 +0100 Sven Joachim <svenjoac@gmx.de> wrote: > >> On Sun, Mar 14, 2010 at 06:04:16PM +0000, Neil Williams wrote: > >> > Personally, I'm not that fussed about Essential anymore - Emdebian just > >> > removes the tag from any and every package automatically. No ill effects > >> > have been identified so far. Sometimes I wonder if Debian actually > >> > needs Essential any more for anything particularly useful or > >> > commonplace. > >> > >> Then you clearly don't understand the purpose of Essential. > > > > I understand the theory, I've just never seen the practical purpose of > > the current mechanism. Yes, it shortens Depends: lines but if the > > dependencies are not listed and the Essential tag is omitted, what > > actually goes wrong? Hmm, phrased that wrong - got distracted instead of taking out that question before sending. The real issue, for me, was the next bit: > It's one thing having a list of packages that can > be omitted from the dependency list but having a tag in the control > file (and Packages file) seems utterly pointless. With a little care, > Essential is irrelevant. ... and having Essential in the Packages file makes it harder than it could be to avoid Essential if the list was in /etc. > The user removes the package and breaks their system. That's no reason to have the flag in the Packages file - that could just be a file in /etc used by apt. The mechanism doesn't warrant being in the Packages file - I'm not seeking to drop the mechanism itself in Debian, just in certain controlled environments like Emdebian and the use of Packages files makes that unnecessarily difficult compared to a file in /etc/. If a suitably reconfigured busybox package is available, lots of Essential packages can be removed without any breakage. The problem is that the implementation of Essential gets in the way of such a fix (which could otherwise be done trivially using Conflicts:). In a Debian chroot: root@holly:/# dpkg -i /home/busybox-extended_1.0_all.deb Selecting previously deselected package busybox-extended. dpkg: regarding .../busybox-extended_1.0_all.deb containing busybox-extended: busybox-extended conflicts with util-linux util-linux (version 2.16.2-0) is present and installed. dpkg: error processing /home/busybox-extended_1.0_all.deb (--install): conflicting packages - not installing busybox-extended Errors were encountered while processing: /home/busybox-extended_1.0_all.deb In a chroot without any Essential: yes tags in Packages files: (Emdebian Grip) root@holly:/# dpkg -i /home/busybox-extended_1.0_all.deb Selecting previously deselected package busybox-extended. dpkg: considering removing util-linux in favour of busybox-extended ... dpkg: yes, will remove util-linux in favour of busybox-extended. (Reading database ... 6149 files and directories currently installed.) Unpacking busybox-extended (from .../busybox-extended_1.0_all.deb) ... Setting up busybox-extended (1.0) ... In this test, busybox-extended was just an equivs package that Provides:, Conflicts: Replaces: util-linux. -- Neil Williams ============= http://www.data-freedom.org/ http://www.nosoftwarepatents.com/ http://www.linux.codehelp.co.uk/
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