Re: [PATCH] bootstrap: When a commit hash is specified, do a shallow fetch if possible

[Bruno Haible]

Hi Glenn,

> I'm thinking of replacing the current comment with
> something along the lines of:
> 
>   Git does not support cloning by commit hash. So attempt a shallow
>   fetch by commit hash to minimize the amount of data downloaded and
>   changes needed to be processed, which can drastically reduce download
>   and processing time for checkout. If the fetch by commit fails, a
>   shallow fetch can not be performed because we do not know what the
>   depth of the commit is without fetching all commits. So fallback to
>   fetching all commits.

That's a good comment. Thanks.

> > Also, I would expect that the GNULIB_REVISION environment variable is not
> > so frequently used, and that the more frequent use is with git submodules.
> > Is it possible to apply the same trick to the git submodules case? Or does
> > the use of submodules always require a deep clone?
> 
> Honestly, I don't have much experience with or knowledge of submodules,
> so I don't feel I can provide a good answer. I suspect that the answer
> is that this trick can be used. I've not looked in to it because the
> project that I'm working on does not use gnulib as a git submodule.

OK, then let's leave that part to the next person who actually observes
the issue in a context with submodules.

Bruno