Re: How to get started using GWL 0.2.0

[Ricardo Wurmus <rekado@elephly.net>]

Hi Jelle,

thanks for giving the GWL a try!

> How do I install GWL, while using a `guix pull'-managed guix (so with
> guile3.0)? As the `guix' that is a propagated input still uses guile2.2,
> this is not as simple as I had hoped it would be.
>
> Currently, I have the following wrapper in $HOME/.local/bin/gwl:
> --8<---------------cut here---------------start------------->8---
> #!/usr/bin/env bash
> export GUILE_LOAD_PATH=$HOME/.guix-profile/share/guile/site/2.2
> export GUILE_LOAD_COMPILED_PATH=$HOME/.guix-profile/lib/guile/2.2/site-ccache:$HOME/.guix-profile/share/guile/site/2.2
> $HOME/.guix-profile/bin/guix workflow "$@"
> --8<---------------cut here---------------end--------------->8---
>
> This wrapper seems to work for stuff like `gwl --help' and `gwl
> --prepare=<file>'. I'd much rather prefer something less terribad though
> :).

Yeah, this is an issue that caused me sleepless nights.  It’s something
I’ve been discussing for some time online and offline, and it’s on the
TODO for the next release.  It is not clear yet how to properly insulate
the GWL from Guix.

The switch from Guile 2 to 3 is a good example of the problem we’re
facing as we try to extend Guix.

> My other issue relates to actually running computations usings
> GWL. Given the following workflow file:
>
> --8<---------------cut here---------------start------------->8---
> process hello-world
>   # { echo "Hello, world!" }
>
> workflow do-the-thing
>   processes hello-world
> --8<---------------cut here---------------end--------------->8---
>
> I can run GWL to both prepare and graph my workflow, yet I get the
> following backtrace when trying actually `gwl --run=<file>': […]

Oh, I’m sorry!  This is a bug.  The code was supposed to pass a list of
mapped input files to a procedure, but it accendentally just passed a
boolean.  That’s clearly incorrect. I’m going to fix this soon.

So I suppose we’ll see a 0.2.1 release soon…  Sorry about that!

--
Ricardo