[Bug-tar] what is the point of archiving /proc "files" if you can't extract them later?

[積丹尼 Dan Jacobson]

Tar can archive these /proc "files" just fine,
but it can't extract them. It gets fooled by its storing a zero file size.
$ tar -cf /tmp/g /proc/[0-9]*/stat
$ strings /tmp/g|head #yup, content of files is in the archive
$ tar --to-stdout -xf /tmp/g #huh, nothing

tar (GNU tar) 1.29
See also
http://stackoverflow.com/questions/3630976/how-can-i-tarball-the-proc-file-system