[bug#41164] [PATCH 0/3] Add 'guix graph --path'

[zimoun <zimon.toutoune@gmail.com>]

Hi Ludo,

Reproducing the example from the manual leads to this error:

--8<---------------cut here---------------start------------->8---
./pre-inst-env guix graph --path -t references libreoffice llvm
guix graph: error: no path from
'/gnu/store/rd24gl402vy5g5sm3azhq13mwdg5fbi1-libreoffice-6.4.2.2' to
'/gnu/store/bcgnx704v408sr7lcy480wcnbkcixwrw-llvm-10.0.0-opt-viewer'
--8<---------------cut here---------------end--------------->8---


On Sun, 10 May 2020 at 16:16, Ludovic Courtès <ludo@gnu.org> wrote:

> > It appears to me not clear in '--help'.
> >
> > display the shortest path between the given nodes
>
> ‘--help’ is not a substitute for the manual though.  Do you have another

Yes for sure.  '--help' is only a remind.  I mean I use it like that:
I know something but I do not remember the exact details on how to use
it (option name, arguments order, etc.)


> wording proposal in mind that is as concise?

display the shortest path from node1 to node2


> As for ‘--path-to’ instead of ‘--path’: I think a path in common
> language is directed (one follows a path from one place to another).

My english is probably not enough good.  (Note that is the same for me
with the french word "chemin".)
To me, "path" is often ambiguous because sometimes it means oriented
and sometimes not; depending on the context: topology, graph theory,
common life: synonymous of road or track and synonymous of route or
direction.

This ambiguity added to the non positional option '--path' appears to
me confusing from where to where.

My 2 remarks come from this ambiguity of the word "path".
Well, maybe it is only me.


> > The "graph" subcommand fits well.  But for example:
> >
> >   guix show emacs --why libffi
> >   guix search emacs --why libffi
> >
> > make sense too -- at least to me. ;-)
>
> Dunno, I’m not convinced.

The main issue with "search" is that the subcommand accepts an
regxexps and so it breaks consistency.  Therefore, I answer to myself:
it is a bad idea. :-)


> > And bikeshedding again, there is a temptation  to pipe the current CLI:
> >
> >   guix graph --path emacs libffi | guix show
>
> ‘guix graph --path emacs libffi | xargs guix show’
>
> Though ‘guix show’ appears to ignore all but one argument, uh.

Yes.  Because it is a pure alias of "guix package --show='.


Cheers,
simon