2007/11/3, Jeff 'codemac' Mickey <jeff@archlinux.org>:
Hello all.
I figure I should start flexing my "zomg coding" muscles a little more for the benefit of arch. What interests me the most right now is optional dependencies. In my local git tree I have added pactest support for testing option dependencies, but I only have one joke of a pactest that checks.
Thanks to Dan, a lot of the work that I really would have a harder time getting right has all ready been done, in adding the right lines to makepkg, libalpm, and pacman so that the optional dependencies are recorded in the db. Right now they are only recognized as simple strings, not as packages with dependency resolution or any of that fun stuff (correct me if I'm wrong here Dan).
The next steps appear to be the following:
* makepkg should recognize the 'pkg:reason for package being option' format I've seen thrown around.
Yes.
* When a package is installed with optional dependencies, we can do a couple different things. o Ask the user right there with the "Install package foo for xyz support?"
Yes.
o Ask the user to explicitly install the optional deps themselves (I don't think this is good at all. This wouldn't keep them listed as "installed as a dependency" and we could just have echo statements in the .install then.)
Could be useful with --noconfirm.
o Check for some kind of /etc/pacman.conf var that lists what packages users don't mind having as optional dependencies, otherwise ask them to install them.
Nah, that will turn into Gentoo's USE flags.
o Something else I haven't thought of.
* When an optional dependency is installed through one of the 3 ways listed above, we need to install it as a dependency, and add it to %DEPENDS%, leave it in %OPTDEPENDS%, and not put it in %REQUIREDBY%
Leave it in %OPTDEPENDS% and do not put it in %REQUIREDBY% and %DEPENDS%.
* When an optional dependency is uninstalled that was only ever installed as a dependency, we can do several things. o We warn the user that they are losing functionality, and remove it from the %DEPENDS% array in the parent. o We let pacman handle it like it does dependcies, this is what we get when we add the optional dependency to just %DEPENDS% and not %REQUIREDBY% o Something else I haven't thought of.
IMO Pacman should handle optdepends not in the same way as depends, so it should be removed from %OPTDEPENDS% array of there parent. About %REQUIREDBY% - probably there should be %OPTREQUIREDBY% ?
* When a package with optional dependencies is removed, it should also remove all other packages that have been moved into %DEPENDS% haven't been explicitly installed. I believe this is funcitonality that we get by adding it to the %DEPENDS% array anyways.
Then any optdepends that doesn't have other packages in %REQUIREDBY% and %OPTREQUIREDBY% should be asked for removal.
I just wanted to get these thoughts out there. I thought I was just going to implement basic -Qi functionality and then address these.. but Dan is a beast and jumped the gun on me.
I would like to hear all of your thoughts on the above ideas, and let's flesh out what action we'd like to see pacman take based on these difference scenarios.
References: http://bugs.archlinux.org/task/4845#comment10357 http://archlinux.org/pipermail/pacman-dev/2006-October/005999.html http://archlinux.org/pipermail/pacman-dev/2007-September/009426.html -- Roman Kyrylych (Роман Кирилич)