Re: [Help-tar] [PATCH] Add --clamp-mtime option

[Paul Eggert]

On 06/04/2015 08:59 AM, Jérémy Bobbio wrote:
> BUILD_DATE="Mon, 01 Jun 2015 18:11:50 +0200"

Yes, that's the hassle I was referring to.  Something has to keep track 
of BUILD_DATE and update it when appropriate.  It would be better if 
this were automated somehow.  (Sorry, I don't have an answer here, just 
pointing out the problem.)

> we currently do:
>
>      find "$DIR" -newermt "$BUILD_DATE' -print0 | \
>          xargs -0r touch --no-dereference --date="$BUILD_DATE"
>      tar -cf archive.tar "$DIR"
>
> And with the `--clamp-mtime` option, we could replace the last lines by:
>
>      tar -cf archive.tar --mtime="$BUILD_DATE" --clamp-mtime "$DIR"
>
> Bonus: actual file metadata are not altered.

OK, but it sounds like you have something working now, and here the 
bonus (actual file metadata not altered) is reasonably minor, so the 
argument for adding this new feature to tar is relatively weak.