bug#25952: offloading empty machines file

[zimoun]

Hi Tobias,

On Mon, 25 May 2020 at 22:32, Tobias Geerinckx-Rice <address@hidden> wrote:

> The issue is that files such as /etc/guix/machines.scm (but this
> applies equally to /etc/guix/acl & so on) are expected to evaluate
> to a sexp.
>
> An empty file does not a valid sexp make, so Guix throws an
> prickly backtrace @ your face & dies.  This is unlike most other
> configuration formats where an empty file or one consisting
> entirely of comments is a no-op.

Hum? I am not sure to get the point.  Are we talking about this kind
of situations, e.g.,

--8<---------------cut here---------------start------------->8---
touch /tmp/empty.scm
guix package -m /tmp/empty.scm -p /tmp/empy
--8<---------------cut here---------------end--------------->8---

or

--8<---------------cut here---------------start------------->8---
echo ";; hello" > /tmp/comment.scm
guix package -m /tmp/comment.scm -p /tmp/comment
--8<---------------cut here---------------end--------------->8---

or

--8<---------------cut here---------------start------------->8---
echo "(define x 42)" > /tmp/answer.scm
guix package -m /tmp/answer.scm -p /tmp/answer
--8<---------------cut here---------------end--------------->8---

?


> We should decide whether ‘’ is a valid sexp (oh dear, philosophy)
> or throw something softer at people.

Throw something more "helping" than e.g.,

--8<---------------cut here---------------start------------->8---
Backtrace:
           1 (primitive-load "/home/simon/.config/guix/current/bin/g…")
In guix/ui.scm:
  1936:12  0 (run-guix-command _ . _)

guix/ui.scm:1936:12: In procedure run-guix-command:
In procedure struct-vtable: Wrong type argument in position 1
(expecting struct): #<unspecified>
--8<---------------cut here---------------end--------------->8---

?


> > Therefore, I am closing.  Feel free to reopen if I misunderstand
> > something.
>
> I think this bug should remain open until it's decided.  What you?

Well, it is a variant of Cunningham's Law, isn't it? :-)
So, let reopen it and decide on the philosophical dilemma. ;-)


Cheers,
simon