Simon Tournier <[email protected]> writes:
> Hi, > > On Fri, 08 Sep 2023 at 19:09, Ludovic Courtès <[email protected]> wrote: > >>>> It would also be pretty bad for closure size: >>>> >>>> --8<---------------cut here---------------start------------->8--- >>>> $ guix size guile-git | tail -1 >>>> total: 106.6 MiB >>>> $ guix size guile-git git-minimal | tail -1 >>>> total: 169.8 MiB >>>> --8<---------------cut here---------------end--------------->8--- >>>> >>>> It’s also not clear concretely how we’d add that dependency. Try >>>> invoking ‘git’ from $PATH and print a warning if it doesn’t work? >>>> But then, what about applications like Cuirass and hpcguix-web? >>> >>> I think we can rely on something like, >>> >>> guix shell -C git-minimal -- git gc >> >> We’re talking about the implementation of a cache (meant to speed up >> operations), that would actually fill said cache plus do a whole bunch >> of expensive operations? Nah. :-) > > I do not think. If I understand correctly, we need to run “git gc” at > some point, therefore git-minimal needs to me around. The question is > how and when. > > Well, maybe I am missing what the bug is about. For me, it is about > running ‘git gc’ for cleaning the Git checkout cache, no? > > > Solution #1. Add git-minimal as inputs. It increases the closure and > the extra load (on average) is about the ratio between the rate of “guix > pull” and the rate of the git-minimal changes. > > Assuming, that people are running “guix pull” once per week and say “git > gc” is run after 50 pulls. (These both number are totally arbitrary and > based on my personal estimate). > > Data Service [1] tells: > > 2023-07-07 15:45:22 2023-09-08 21:22:08 > 2023-05-11 16:10:48 2023-07-07 14:21:45 > 2023-05-01 16:40:08 2023-05-11 14:36:16 > 2023-04-25 13:34:54 2023-05-01 15:19:55 > 2023-04-25 13:34:54 2023-09-08 21:22:08 > 2023-03-06 17:22:28 2023-04-25 12:27:33 > 2023-01-17 23:49:19 2023-03-06 16:48:43 > 2022-11-08 13:06:42 2023-01-17 15:11:47 > 2022-10-08 05:14:46 2022-11-08 09:56:31 > 2022-09-06 15:00:08 2022-10-08 04:15:43 > 2022-08-13 22:02:31 2022-09-06 12:58:52 > … > > It means that an user will download ~10 times git-minimal for nothing. > > > Solution #2. The one I am proposing. :-) Download git-minimal only > when Guix needs it for running “git gc”. Yeah, there is probably a > small overload with some operations. But, I bet this overload is much > smaller than the one of solution #1. > > Well, it depends on the number of times people are updating the cache vs > the rate of change of git-minimal. > > For sure, if one updates 100 times per week the cache, having > git-minimal as inputs is far better. But I do not think that the > regular usage on average. :-) > > That’s why I am proposing to have an option for turning off this “git > gc“ operation. > > Well, we have lived since years without running ‘git gc’ so running it > once per year on average is probably enough to keep the cache size > reasonable. And git-minimal is changing every month. > > > Maybe, there is some solution #3. ;-) > > Cheers, > simon > > > 1: > https://data.guix.gnu.org/repository/1/branch/master/package/git-minimal/output-history Please don't create another situation like with guix system roll-back, where a crucial sysadmin operation doesn't work without network access. Or at least make it configurable, so things that are likely to be needed for future operations are pre-fetched.
