How to compute SWHID? (with Guix/Disarchive)

[zimoun]

Hi,

Giving a look at Disarchive, I found how to compute Git-based
serialization hash and somehow serialization methods of "guix hash"
needs some clearning; considering '--recursive' is 'nar' serialization
which is a better name.  Anyway, see [1]. :-)

I would like to add SWH-based serialization hash but I do not find if
a function already does the hard work.  Any pointer?

Moreover, I would like to add* a new export format to "guix show"
using BibTeX format proposed by SWH.  It would help when writing
paper. ;-)

*add: discussed long time ago but because I was not writing a paper
using tools deployed by Guix, I was not bitten enough to complete. ;-)

1: <https://issues.guix.gnu.org/51307#17>


Cheers,
simon