bug#65241: 30.0.50; Cannot clone NonGNU ELPA

[Stefan Monnier via "Bug reports for GNU Emacs, the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>]

>> $ git clone git://git.savannah.gnu.org/emacs/nongnu.git
>> Cloning into 'nongnu'...
>> remote: Counting objects: 425227, done.
>> remote: Compressing objects: 100% (145570/145570), done.
>> error: object 2699d230e3b592ae42506d7b5c969a7ac6a4593c:
>> zeroPaddedFilemode: contains zero-padded file modes
>> fatal: fsck error in packed object
>> fatal: fetch-pack: invalid index-pack output
>
> I thought we fixed that, but maybe that was only for GNU ELPA?

Indeed we had such a problem over in `elpa.git` and we solved it, but
that problem can re-appear any time we pull from some (old(enough))
upstream repository.

> Stefan M, do you have any comments?  Is there anything we could do here?

`git show 2699d230e3b592ae42506d7b5c969a7ac6a4593c` suggests this is
part of `coffee-mode`, and indeed:

    git -c 'Transfer.fsckObjects=true' clone https://github.com/defunkt/coffee-mode

gives me the same warning (tho it's a warning rather than an error).

Just use

    git -c 'Transfer.fsckObjects=false' clone ...

to workaround the problem.  I think the problem is fundamentally in
Git's camp: the format that `fsckObjects` enforces is incompatible with
the data it used to generate, and since rewriting history is a big
problem, it's not something that can be fixed.


        Stefan