Re: triggers wishlist

[Ian Jackson <ian@davenant.greenend.org.uk>]

Petter Reinholdtsen writes ("Re: triggers wishlist"):
> [Michael Biebl]
> > I don't understand, why it shouldn't be possible, that a single
> > update-rc.insserv run, reoders *all* init scripts in one go. You
> > could still skip the ones, which will cause loops or have no
> > dependency information.
> 
> Well, there are two things that need to be done as insserv work today:
> 
>  - Call update-rc.d in dependency order when adding new scripts to the
>    boot sequence (one call is not going to work).  It refuses to
>    install a script (and in consequence, the package) if the scripts
>    hard dependencies are not already inserted into the boot sequence.

Is update-rc.insserv actually slow at all ?  If so then deferring this
work with a trigger may help: you'll only run it once at the end.

>  - Refuse to install a package that introduces a dependency loop,
>    while allowing those that do not introduce a loop to install, to
>    avoid getting an unstable boot sequence (as in, there is no way to
>    know how to order the scripts involved in a loop).

This is wrong, I think.  What you seem to be essentially asking for is
a pre-dependency, which is not right for general use.  Even worse, a
kind of synthetic predependency which just cases preinsts to fail,
which defeats attempts by packaging tools to order the unpacks to meet
the restrictions.

Ian.