GNU sharutils generated archive license

Hello,

A query has arisen in our organisation as to whether the archives created by
the GPLv3-licensed 'shar' command must also fall under the GPLv3.

I assumed there is no intention for this to be the case.

However, looking at the GPL FAQ[1],

> [Output is copyrightable only] if substantial parts of the output are copied
> (more or less) from text in your program.  For instance, part of the output
> of Bison (see above) would be covered by the GNU GPL, if we had not made an
> exception in this specific case.

Due to the nature of shar, I believe it does copy parts of its program text
into the archives - in particular the shell code that "extracts" the archive.

I can find no mention of a Bison-like disclaimer in the sharutils license. Is
this an oversight?

Thanks,

Daniel

[1] https://www.gnu.org/licenses/gpl-faq.html#GPLOutput