Re: git-fetch: default globally to --no-tags
- From
Junio C Hamano <gitster@pobox.com>
- Date
- Nov 19, 2014, 18:45 UTC
- Message-ID
- <xmqqr3wzrpur.fsf@gitster.dls.corp.google.com>
- In-Reply-To
- <20141119030523.GO22361@norris-Latitude-E6410>
Brian Norris <computersforpeace@gmail.com> writes:
> --- TL;DR ---
You usually have TL;DR at the beginning to help people save time; having it at the end forces the whole thing to be read and would not help anybody. ;-)
> My email boils down to two questions: > > (A) Has there been progress on implementing a proposal like in [2]?
I do not think so, and also I do not agree that "mirror everybody else's ref hierarchy into separate namespaces" is necessarily a good idea, especially for tags, whose reason of existence is to give people a way to have anchoring points they agree on to have a shared world view necessary to move things forward.
In other words, talks in [2] are attempting to solve a wrong problem. The problem people want to solve is to have a mechanism to keep private anchoring points that are not necessarily shared project wide, which tags in refs/tags hierarchy is *not*.
Like it or not, tags are meant to be used for globally shared anchoring points and the whole machinery (e.g. "fetch" that auto-follows tags, "clone" that gives refs/tags*:refs/tags/* refspec) is geared towards supporting that use pattern, which will be broken by moving tags to per-remote namespace.
I can see "git tag --local foo" that creates refs/local-tags/foo and also adding a mechanism to propagate local-tags/ hierarchy just like heads/ hierarchy is propagated per-remote as a solution to that problem that does not break the "release tags" use case, though.
> (B) Can we allow disabling (auto)tag-fetching globally? Like: > > git config --global remote.tagopt --no-tags
Using remote.<variable> as a fallback for remote.<remote>.<variable> may be a useful addition, not limited to <variable>==tagopt case.
This is a tangent, but it is an important one because we are talking about "tagopt" specifically. I think we should start deprecating "*.tagopt --[no-]tags". It started as a quick-and-dirty hack back when "git fetch" was a shell script Porcelain, where it made it easy to write things like this in its implementation:
tagOpt=$(git config "remote.$name.tagopt")
git fetch $tagOpt $name $argswhich gives an impression that any command line option can go there (e.g. as if you could set "remote.*.tagopt = --frotz --no-tags") and "git fetch" implementation, even after it is redone in C, must forever parse it as if it is part of a shell command line (e.g. splitting at $IFS, unquoting the shell quotes and interpreting as if they came in argv[]).
This is ugly and simply unmaintainable, and we should transition away from that, by doing something like:
(1) Add remote.*.tags configuration, which defaults to 'follow',
but can be set to 'true' or 'false'. Accept '--tags' as a
synonym to 'true' and '--no-tags' as a synonym to 'false'. * when set to 'follow', allow auto-following tags (the default).
* when set to 'true', act as if --tags is given.
* when set to 'false', act as if --no-tags is given. (2) Deprecate remote.*.tagopt configuration. When it is used, give
a warning about deprecation and encourage users to move to
remote.*.tags setting.(3) Wait for several release cycles.
(4) Remove remote.*.tags configuration support at a major version
boundary.Needless to say, support for remote.<variable> as a fallback for remote.<remote>.<variable> for any <variable> can be done in parallel to this tangent topic.