---
title:
	Guix and Shepherd
sidebar: true
misc_links: >-
  <a href="set_up_build_environments.md"  target="_blank">Set up build environments</a><br>
abstract: >-
  I know nothing about Guix.  This file exists to record my learning
  experience.\

  \

  The plan is to be able to install Guix on debian, then load a reproducible
  configuration file so that I can instantly and reproducibly produce a
  host setup the way I want it.  (Which nix, lacking its own init
  system, cannot quite do, because one always wants to run services.)
...

Guix is primarily a package manager with a declarative functional language
as its package manager.

Which makes it possible to reproducibly create a setup.
Unfortunately the packages are hard to customise,
because access to the
configuration files is restricted and non trivial -- you have to derive your own package from an existing package

Guix solves the problem of dll hell by having any number of configurations living on the same machine --
which leads to massive and rapid accumulation of garbage.
Garbage collection is very slow, and requires either a lot of ram or a lot of swap (12GB swap recommended.
This is a feature I do not want, but wind up suffering, for the advantage of reproducible setups.

To avoid bloat, can use a strategy of re-install from scratch, which Guix makes less painful.

"With Guix System, you declare all aspects of the operating system configuration and Guix takes care of
instantiating the configuration in a transactional, reproducible, and stateless fashion
(see [System Configuration](https://guix.gnu.org/manual/en/html_node/System-Installation.html))."


# What Guix is

A Guix package is a pure function, which generates the install
as directory identified by its hash in `/gnu/store` and then a symbolic link
in the users directory references the package by human readable name, analogous
to git having branch names that point to commits.

Which is great if you have a lot of users each of which might want a different
version of software, but I want to install stuff that will run under
the init system, Shepherd.

The package manager is a great pile of such pure functions,
but if you want to install stuff that is fully configured the way you want it configured,
you are going to have to derive a packages from an existing package

The Guix install system, Shepherd, cannot be a pure function, there can only be one http service,
one wireguard service, and so forth.  It has to be the escape hatch that makes a purely functional
system actually do things by not being a purely functional system, akin to Haskell Monads,
an isolated piece of procedural code that make all the purely functional code actually do something.

# Install Guix and Shepherd

not yet begun