Re: Pre-Depends according to sarge_rc_policy.txt
On Sat, Sep 06, 2003 at 07:11:13PM +0200, Thomas Hood wrote:
> [quotation from sarge_rc_policy.txt:]
> > > Packages listed in "Pre-Depends:" must be (adequately) functional
> > > when unpacked but not installed.
>
> [quotation from policy:]
> > > When a package declaring a pre-dependency is about to be
> > > _unpacked_ the pre-dependency can be satisfied if the depended-on
> > > package is either fully configured, _or even if_ the depended-on
> > > package(s) are only unpacked or half-configured, provided that
> > > they have been configured correctly at some point in the past
> > > (and not removed or partially removed since). In this case, both
> > > the previously-configured and currently unpacked or
> > > half-configured versions must satisfy any version clause in the
> > > `Pre-Depends' field.
>
> On Sat, 2003-09-06 at 14:06, Santiago Vila wrote in debian-devel:
> > Does the word "adequately" not summarizes pretty much the "long version"
> > in policy?
>
> The sarge_rc_policy text doesn't summarize the policy text. Policy
> doesn't impose any special requirements on a pre-depended-on
> package; policy imposes a requirement on dpkg, telling it that it
> may only install the pre-depending package if the pre-depended-on
> package has already been unpacked and configured.
I think your summary of policy is inaccurate. The pre-depended-on
package doesn't have to be configured; it merely has to have been
configured at some point in the past. Thus, pre-depended-on packages
have to be prepared to be functional in the most common case of being
unpacked but not configured (if we assume that packages are upgraded
more often than they're installed, which seems rather likely to me).
This is a requirement imposed by policy on pre-depended-on packages.
AJ's requirement is fractionally stricter than policy's, but packages on
which other packages pre-depend should be playing it safe anyway. I
think that very much the same kind of care is needed to satisfy AJ's
requirement and to satisfy policy.
Cheers,
--
Colin Watson [cjwatson@flatline.org.uk]
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