Re: RFC: subcommand to pause/resume builds

[John Soo]

Hello Tobias :),

Tobias Geerinckx-Rice <me@tobias.gr> writes:

> Ludo',
>
> Ludovic Courtès 写道：
>> First, note that the daemon is unaware of “packages”, it only knows
>> about “derivations”.
>
> Derivations have a (file) name, which can be matched with a regex
> allowing one to, say, ‘pause libreoffice’.  It works in practice.
> I do this often & it's *extremely* convenient.

This feels close to little sed/awk pipelines.  Which is not to be
entirely dismissive. I like the compositionality of these tools.  In
fact I mentioned earlier that it might be good to send arbitrary
signals. But why not let kill (shell or scheme) do that?  All we would
need is to filter and format pids in a composable way (on the scheme
side and the shell side). That has the benefits of remaining agnostic on
side effects in builds (let the user decide what they are comfortable
with) and being more composable.

Maybe flags like this would be enough:

guix processes --session=<derivation-regex> ...

to get something like

5555
1212
343434
...

> Sometimes even necessary, because I have a habit of starting too many
> builds ;-)  It's nice not to lose 6h of work.

Indeed. This already saved me hours after learning it yesterday.

> Not every handy hack needs to be upstreamed though.  ‘It's fugly’ is a
> strong argument in Guixland, and I like that.

Same.

> T G-R, now thinking about acronyms like ‘CRIU’ and what a next-level
> hack would look like...

Yeah seems like functional build systems would ideally be
order-independent, pause/resumable, and the build steps time-travelable
themselves. But that's a cool aside for now.

Thanks for the tips!

John