Bug#216682: apt/preferences: need for pinning a given (set of) package per release
On Sun, Oct 19, 2003 at 10:34:47PM +0200, Yann Dirson wrote:
> after practicing the use of the feature, I still do not fully
> understand all details, and I'd like, firstly, to disambiguate things
> in my mind, and, secondly, to find a way to make that more clear in
> the manpage.
Let's summarize what I think I have understood, from both versions of
the doc, and from experimentation. Since most of this either
complements material in the manpage, or is simply not explained in the
manpage, I'd like to have your opinion on this before I start to work
on the real doc. This appears to me[composing-this-mail-instead-of-
taking-overdue-sleep-time] as summarizing the issues that puzzled
me[desperately-trying-to-make-this-work-in-real-life]. YMMV. Mine
too, especially on tomorrow, I suppose.
- there is a specific form (identified by a single package name) and a
general one (identified by "Package: *")
- the general one allows to assign a priority to the version of all
packages provided by a given (set of) repository(ies) (ie. a line from
sources.list), regardless of what this version is. The computed
priority can then be observed in "apt-cache policy" output on the
left of the relevant repository line.
- the specific one allows to assign a priority to a given (range of)
version(s) of a given package, based on various criteria (see below).
The computed priority can then be observed in "apt-cache policy"
output on the right of the matched package version, even when not
using the package version as criteria. Additionally, a possible
display bug in "apt-cache policy" causes the elected priority to get
displayed next to all other available versions.
- for a given package, only the last paragraph of the specific form is
read, all previous ones are ignored without notice. Because of this
the layout of "apt-cache policy" output seems strange, and this could
account for the above-mentionned "possible display-bug".
- FIXME: I did not experiment yet with equivalent combinations of the
general forms
- FIXME: given independant scores for the general and specific forms,
I suppose the candidate version is the one which has the best eligible
score in either slot ?
- There are 3 ways of selecting (pinning) the (range of) versions a
paragraph refers to: by release, by version, and by origin. A
paragraph of the general form can only use a "release" Pin, whereas a
paragraph of the specific form can use any Pin form.
(or maybe 'origin ""' is the only one accepted by the general form ?
I did not test this one, but it seems 'origin ftp.debian.org' was
ignored for the general form (unless I missed something else),
although it worked for the specific from)
(those 3 forms are adequately described in the old doc. The new doc
completely forgets to document "origin" pins, only mentions release
pins in the doc about the general case, and (correctly) only mentions
version pins in the doc about the specific case. I think those
issues are orthogonal enough to deserve being described separatedly.)
Regards,
--
Yann Dirson <ydirson@altern.org> | Why make M$-Bill richer & richer ?
Debian-related: <dirson@debian.org> | Support Debian GNU/Linux:
Pro: <yann.dirson@fr.alcove.com> | Freedom, Power, Stability, Gratuity
http://ydirson.free.fr/ | Check <http://www.debian.org/>
Reply to: