[systemd-devel] RFC: creating a set of systemd RPM macros across distributions ?

[Kay Sievers]

On Wed, Jul 6, 2011 at 11:15, Frederic Crozat <fcrozat at suse.com> wrote:
> Le mardi 05 juillet 2011 à 23:39 +0200, Lennart Poettering a écrit :

>> The simple fact is that we need a dependency on systemd anyway in the
>> RPMS to get the ownership for the units directory right. Now, if we have
>> "Requires: systemd" in the header, why do we also need "Requires(post):
>> systemd"? What does this buy us?
>
> Requires(post/preun/postun) on the package containing systemctl is
> needed as soon as systemctl is called in %post/preun/postun. A simple
> Requires is not enough, because you might end up installing systemd and
> the package requiring it in the same rpm transaction, but in the
> incorrect order.

That's just not true. The 'Requires: systemd', which we always need
anyway, will ensure the proper install ordering just fine during a
transaction. Otherwise tons of similar things in that context would
just not work like they work today.

Scriptlet dependencies are needed if cyclic loops need to be broken,
means systemd.rpm requires itself some other package which itself has
'Requires: systemd'. Then the explicit scriptlet dependency binds
stronger than the normal Requires:, and ensures loop breaking at that
point in the circle.

Or scriptlet dependencies are useful if the required package should be
able to get un-installed later, which isn't the case for systemd.

I'm not saying we it might not be useful for corner cases, and if we
decide so, we might end up doing something like this, but it's surely
not *needed* at all for the common case, and if we need the reverse
for some special packages it might even get in our way.

Kay