Re: Setting up Guile for use with Guix

[Amirouche Boubekki]

On 2018-08-17 14:34, HiPhish wrote:
> Hello everyone,

Hello HiPhish,


I am a regular Ubuntu, guix user and I develop stuff using guile.


> I have Guix up and running on my Kubuntu 18.04 machine. I installed it
> manually
> from the binary: I first installed Guile 2.2.3 via apt, then I 
> installed Guix.

Wow! ubuntu has a quiet recent guile! that's good news!

What matters when installing guix package manager on top another 
distribution is
only the shell and PID 1. If you use zsh or something fancy as shell, 
you might need to
adapt some of the instructions from the manual. If you don't rely on 
systemd
or upstart again, you will need to adapt the direction given in the 
manual which can
boil down to run guix-daemon as root in the background in a screen. Poor 
man's service,
I know, but it works.

Another thing that might matter is some kernel options, but that is only 
relevant
if you use guix containers. I did not try guix containers for a looooong 
time,
so it might work out of the box with recent kernels.

Since I am a using both bash and systemd I just follow the instructions 
from
the manual I have nothing specific to do.

The only thing I struggle with is the shell environment variables. That 
is
what outputs the following command as a regular user:

  guix package --search-paths

I just reinstalled ubuntu and guix from binary and I have setup my guile 
dev
environment to run and develop my guile project. Here is the output of 
the above
command:

----->8------ START 
----->8----------->8----------->8----------->8----------->8----------->8------

export 
PATH="/home/amirouche/.guix-profile/bin:/home/amirouche/.guix-profile/sbin"
export 
GUILE_LOAD_PATH="/home/amirouche/.guix-profile/share/guile/site/2.2"
export 
GUILE_LOAD_COMPILED_PATH="/home/amirouche/.guix-profile/lib/guile/2.2/site-ccache:/home/amirouche/.guix-profile/share/guile/site/2.2"
export XDG_DATA_DIRS="/home/amirouche/.guix-profile/share"
export GIO_EXTRA_MODULES="/home/amirouche/.guix-profile/lib/gio/modules"
export 
GIT_SSL_CAINFO="/home/amirouche/.guix-profile/etc/ssl/certs/ca-certificates.crt"
export GIT_EXEC_PATH="/home/amirouche/.guix-profile/libexec/git-core"
export 
PKG_CONFIG_PATH="/home/amirouche/.guix-profile/lib/pkgconfig:/home/amirouche/.guix-profile/share/pkgconfig"
export SSL_CERT_DIR="/home/amirouche/.guix-profile/etc/ssl/certs"

----->8------ END 
----->8----------->8----------->8----------->8----------->8----------->8------

That is actually the content of ~/.bash_profile file

I added an export EDITOR=emacs because emacs is my editor of choice. For 
some reason,
I always need to source ~/.bash_profile when I want to use guix in a new 
shell.

> I wanted to do some more serious Guile work involving libraries, and 
> since
> Guile does not have a package manager of its own, using Guix is the way 
> to go.

If you try guile-hall, don't forget to send us feedback, please :)

> Here is my question: how do I properly set up Guile on Guix? I already 
> have
> Guile set up system-wide (via apt), but packages like Haunt list Guile 
> as
> their
> own dependency. Will this install a second Guile for me (one 
> system-wide from
> apt and one for the Guix profile from Guix)?

It depends on how haunt package definition is written. Because of how 
guix
works, you can use a program that uses guile without having 'guile' 
command
available. Similarly, it makes it possible to run two programs at the 
same
time that depends on different versions of the same library.. that's 
something
that is very difficult to do outside guix and nix. It's one of the 
consequences
of packaging is done. This leads to the point that in theory, you SHOULD 
never
install _libraries_ in your user profile ie. the regular / default 
profile because
no executable will use it. Default guix profile, SHOULD, I THINK, only 
contain data
and executables.

I say SHOULD everywhere because that's not the way *I* work. Indeed, I 
install
libraries in the user profile instead of relying on guix environment see 
[0].
Because I find guix environment not good enough for my use case. But I 
did not
come around understanding/explaining what the problem is. (The issue, I 
have, is
that I only know how to use environment with a guix.scm package 
definition or manifest.
I don't like that way. I prefer to have a directory with my profile next 
to my
project and then do a bunch of 'guix package -i guile-wiredtiger'. It's 
prolly possible
but I never did it)

[0] 
https://www.gnu.org/software/guix/manual/en/html_node/Invoking-guix-environment.html

Don't skip environment because of me. I actually use environments when I 
need to hack
on guix itself (because the guix.scm file, aka. the file that setups the 
environment
profile, is already written...)

> Should I uninstall the Guile from apt?

You can and you SHOULD. To avoid any misunderstandings.

> How do I even set up Guile to work with Guix packages? I don't have any
> installed yet, but when I open a regular Guile REPL and type
>
>     (use-modules (guix gexp))
>
> I get an error that the '(guix gexp)' module could not be found. So 
> obviously
> I need to set up Guile first before I can use it to script Guix. I 
> assume the
> same is true for other Guile libraries.

That is not a good example use of hacking on a guile project because 
guix is using
it's own version of guile which might be different from the version of 
guile you
installed in your profile... again because functional packaging. If you 
want to
hack on guix follow the README that you can find in guix git repository 
at [1]

[1] git clone https://git.savannah.gnu.org/git/guix.git

> Speaking of which, if there are two libraries, and each one lists a 
> different
> version of Guile as its dependency, will it be possible to use both 
> libraries
> in the same project?

In the case of guile you can not do that. Different executables (with 
different package
definitions) can use different version of guile. That being said two 
executables coming from the
same package get the same guile version and the same libguile. That is a 
feature that
COULD be implemented in Guile VM but is not. It's AFAIK very rare that a 
VM can handle
multiple versions of the same library in the same executable... The only 
case I know
is JavaScript... try to search://guix+npmjs here be dragons.

> I don't quite understand the concepts of functional
> package management yet. How do I need to set up my environment for 
> working
> with
> libraries? Am I supposed to create a custom per-project profile, switch 
> to
> that
> profile while working, and then switch back to normal once done?

Hey seems like the above rambling was not entirely necessary. Like I 
said,
I don't use profile to hack on my guile projects and install things like 
guile-wiredtiger
in my default profile, but if you know your way around guix profiles you 
can work that
way too. It is a recommended practice ;]

> In my case I want to install Haunt. There are two packages: 'haunt' and
> 'guile2.0-haunt', the only difference seems to be which version of 
> Guile they
> require. Right? To make matters more complicated, Haunt is not just a 
> library,
> but also a stand-alone command-line program, which (I presume) includes 
> its
> own
> Guile implementation, and so I need to make my own libraries available 
> to
> Haunt's Guile, not the Guile I installed on my system.

I don't use haunt myself. Lookup the README of the guix website, there 
is
an example of how to setup an environment for building a haunt weblog 
using
an environment https://git.savannah.gnu.org/cgit/guix/guix-artwork.git/

> I just need to wrap my head around the functional way of package 
> management,
> instead of the classical "lol, just throw everything into the global 
> state"
> system. Thank you in advance for your responses.

That's basically what I still do because I don't fully know my guix-fu 
on guix
profiles. I am sure you can do better! The silver lining is that I am 
living proof
that you don't need to know all of guix to guix.

--
Amirouche ~ amz3 ~ http://www.hyperdev.fr