Subject: Re: [PATCH] Recommend "git gc --auto" instead of "git prune"

From: Denton Liu <[email-masked]>
Date: Sun, 7 Jun 2020 16:45:31 -0400

Hi all,

On Sun, Jun 07, 2020 at 10:10:19AM -0700, Junio C Hamano wrote:
> "brian m. carlson" <[email-masked]> writes:
> 
> >> diff --git a/builtin/gc.c b/builtin/gc.c
> >> index 8e0b9cf41b3..3833a3de332 100644
> >> --- a/builtin/gc.c
> >> +++ b/builtin/gc.c
> >> @@ -692,7 +692,7 @@ int cmd_gc(int argc, const char **argv, const char *prefix)
> >>  
> >>  	if (auto_gc && too_many_loose_objects())
> >>  		warning(_("There are too many unreachable loose objects; "
> >> -			"run 'git prune' to remove them."));
> >> +			"run 'git gc --auto' to remove them."));
> >
> > I'm not sure this is correct.  If we have just expelled a large number
> > of objects from a pack into loose objects because they're no longer
> > referenced, it's possible we may trigger another git gc --auto on the
> > next time we run a command.  If so, no amount of git gc --auto is going
> > to help here; you really have to run git prune.
> 
> Correct.  When running manually, after noticing the need to do a GC,
> it is a mental bug to add "--auto" to it, I would think.

Sorry about the confusion, when I was responding to the original
issue[0], I mistakenly typed the wrong thing. I meant to suggest
replacing it with `git gc --prune=now`, _not_ `git gc --auto` but I
guess I had my wires crossed. With this in mind...

The rationale behind this change is that John wanted to add bash
completions for `git prune`. However, I noted that prune is a plumbing
command and users should opt to use `git gc` instead. He mentioned that
sometimes when auto gc runs, it tells the user that they should run
`git prune` so I suggested (meant to suggest) replacing the command with
`git gc --prune=now` instead so that users could call the porcelain.

[0]: https://github.com/gitgitgadget/git/issues/642