Re: Adding plumbing subcommand 'derivation'?

[Christina O'Donnell]

Hi,

In the interest of throwing ideas out there, and with the caveat that 
this is rather uninformed:

I think having  a derivation sub-command makes the most sense to me. E.g.

`guix derivation show` for `guix drv-show`
`guix derivation update` for `guix drv-drv` (or 'refresh' or 'fix')

I have also been thinking that it'd potentially be useful to have 
something like:

`guix derivation edit /gnu/store/...-xyz.drv`

Which then produces a temp directory that you may edit with whatever 
tools you like, then on command checks for changed files, recompute 
hashes recursively, and puts the modified derivations and back into the 
store. I think this would be mainly be useful as a debugging tool or for 
changes that no longer build, for cases where the new `guix derivation 
update` wouldn't work.

On the tangential subject of plumbing commands, I've also started to 
write a `guix store` command that simply exposes functions in (guix 
store) as a command line interface as a way of learning the internals of 
Guix.

This would have sub-commands like:

`guix store get-references`
`guix store get-referrers`
`guix store info` - dumps the `path-info`
`guix store put xyz` - puts xyz into the store as a fixed derivation 
binary blob.

I say this as a way of clarifying the design of `guix derivation`, not 
as extra stuff that needs go in at the same time. Most of these commands 
might be deemed unnecessary.

Alternatively, as you say, Ricardo:

`guix inspect get-references`
`guix inspect get referrers`
`guix inspect path-info`
`guix inspect show-derivation`

However, in that case, another home would need to be found for drv-drv 
at minimum since I wouldn't expect 'inspect' to modify anything.

Kind regards,

Christina

On 18/04/2024 09:40, Ricardo Wurmus wrote:
> Hi Simon,
>
> > So I propose to add the plumbing command ’derivation’.  Any objection?
> I think it's useful to have.  To avoid proliferation of sub-commands, do
> you think we could put this under "inspect", a generic sub-command for
> all sorts of as yet to be invented introspection tools?