bug#33124: Cuirass: register GC roots for evaluations under /var/guix/gcroots

[ludo@gnu.org (Ludovic Courtès)]

Hi Clément,

Clément Lassieur <clement@lassieur.org> skribis:

> I think the goal here is to make sure that the builds that resulted from
> of 1) important evaluations (releases) and 2) recent evaluations aren't
> garbage collected.
>
> <sneek> snape, civodul says: i think Cuirass should register GC roots for its
> 	evaluations under /var/guix/gcroots
> <snape> [...] How many such evaluations should be registered?  If all
> 	are registered, we'll run out of space won't we?  So would it be
> 	like the last 15 or something?
> <civodul> snape: i think we'd register all of them and use (guix cache) to
> 	  automatically wipe old ones periodically  [09:53]
> <civodul> snape: when there's a release we could manually stash important
> 	  evaluations away so they won't be deleted
> <civodul> so i'd just create one subdir for each eval say in
> 	  /var/guix/profiles/USER/cuirass/evaluations  [09:54]
> <civodul> and that'd contain a bunch of symlinks to both the .drv and the
> 	  outputs

I went ahead and implemented a simple version of this in commit
d4623d50edac4a6e81f5986a91c2818f5fc4965d.

Let me know what you think!

Ludo’.