Re: triggers wishlist

[Mike Bird <mgb@yosemite.net>]

On Sun March 30 2008 23:37:48 Petter Reinholdtsen wrote:
>  - 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).

It's reasonable to try to keep boot dependency loops out of the archive,
and in particular to prevent boot dependency loops from migrating into
testing.  That solves 90% of the problem.

Yet boot dependency loops will arise in sid or during upgrades or because
of pinning or otherwise.  Refusing to install a package which creates
a loop is only one option, and not necessarily the best option as it
makes updates and dist-updates harder.  Options include:

0) Issue error message and abort package installation.
1) Issue warning message and try to boot cliques in parallel.
2) Issue warning message and try to boot cliques in lexical order.
3) Issue warning message and try to boot cliques in installation order.

--Mike Bird