Re: Configuration System's Handling of Missing Packages

[Ricardo Wurmus]

Keith Osterheld <address@hidden> writes:

> What's the difference between a package being downloaded into /gnu
> instead of the system profile, and when should I use the package module
> instead of installing it normally? To me it seems like the only reason
> for using a package module is for easier deployment, is that right?

*Every* package is installed into /gnu.  Profile generations, too, have
their own directory somewhere in /gnu.  They are *also* linked
elsewhere, such as ~/.guix-profile or the system profile.  When a
package is installed it is first built or downloaded into some place in
/gnu/store, and then a new profile generation in /gnu/store is created,
which contains a link to the new package.

Package modules have nothing to do with package installation.  All
packages in Guix are Scheme expressions bound to names.  These bindings
are *defined* in modules.  If you want to refer to any package
expression by name in a programme or another expression (such as the
system configuration or a manifest) you have to make sure that the
module is loaded in the current file.

~~ Ricardo