[maemo-developers] [maemo-developers] library updates

[From: Tomas Frydrych]

Hi,

Neal H. Walfield wrote:
> At Thu, 20 Jul 2006 18:06:31 +0100,
> Tomas Frydrych wrote:
>>> how are updates of library packages which are not visible in the
>>> application manager expected to work? We just noticed that when updating
>>> gpe-calendar the updated libeventdb does not get installed. libeventdb
>>> is visible because its section currently is "user/libs", so in this case
>>> i can install the update but what if the package is not visible?
>> I think you just need to make sure that the main package includes
>> appropriate version number in the dependency declaration, not just the
>> library name; at least that seems to work for me.
> 
> That's a hack and a poor one at that.  Versioned dependencies are used
> when the applications depends on a particular ABI version of a
> library.  I think it is a bad idea to abuse this.

> What florian wants is `apt-get upgrade' functionality, i.e. install
> updates for any installed package.

If the application needs a particular version of the library, or higher
than (for whatever reasons, not just ABI compatibility), then the
package should declare that -- that is not a hack; if the application
does not need a newer version than is on the device already, then this
question becomes entirely moot. (Why should you, the application
distributor, care about it getting upgraded?)

> The application manager could use
> the following predicate to determine if an application is up to date:
> if and application and all of its dependencies (direct and indirect)
> are the latest version available (respecting APT::Default-Release and
> the pin settings, of course), it is up to date. This would cause a
> bit of confusion when a new version of a commonly used library, e.g.,
> GTK+, becomes available as then pretty much all applications
> indirectly depend on it.  These can be exclude by having a base system
> container.

Yes, to mark applications as not being up to date because there is a
newer version of a library they use, even though they do not need the
newer version, would seem to me rather unintuitive from the user point
of view. Perhaps the manager should simply offer the option to upgrade
packages that are not normally visible in the UI, but that it installed
with the applications (it should not be hard to do; it already knows to
to remove the 'invisible' dependency packages when you remove the main
package).

Tomas