Re: default tar format for "make dist" and patch file length

[Maxim Cournoyer]

Hello,

[...]

>>> A different angle might be to actually use a different tar format:
>>>
>>>   https://www.gnu.org/software/tar/manual/html_section/Formats.html
>>>
>>> I would guess "make dist" is using the tar "v7" format, based on the 99
>>> character length limit for files. Most of the other formats have no file
>>> length limit or a longer limit.
>>
>> Yes, we could also do that.
>
> Struggling to figure out how to do that; seems automake is very inclined
> to use the old format... anyone with sufficient auto* skills to try and
> upgrade the "make dist" to pass one of the newer --format= arguments to
> tar?

Reading the Automake manual (info (automake) List of Automake options) I
stumbled on this:

    ‘filename-length-max=99’
         Abort if file names longer than 99 characters are found during
         ‘make dist’.  Such long file names are generally considered not to
         be portable in tarballs.  See the ‘tar-v7’ and ‘tar-ustar’ options
         below.  This option should be used in the top-level ‘Makefile.am’
         or as an argument of ‘AM_INIT_AUTOMAKE’ in ‘configure.ac’; it will
         be ignored otherwise.  It will also be ignored in sub-packages of
         nested packages (*note Subpackages::).

This makes me think that Automake is simply configured out of the box to
keep the file names as portable as possible (it doesn't mean it uses
tar-v7 itself, IIUC, though I haven't checked).

Seems a good thing to be as portable as can be, especially since 200
chars patch file names wouldn't look good in the sources anyway ;-).

Thanks,

Maxim