Ludovic Courtès (2016-01-12 23:28 +0300) wrote:
> Alex Kost <alez...@gmail.com> skribis:
>
>> For a usual profile, packages are placed in a profile directory itself,
>> but for a system profile, packages are placed in 'profile'
>> sub-directory. So we need to do some special cases for system profiles
>> to find packages there as well.
>
> [...]
>
>> +(defun guix-packages-profile (profile &optional generation system?)
>> + "Return a directory where packages are installed for the
>> +PROFILE's GENERATION.
>> +
>> +If SYSTEM? is non-nil, then PROFILE is considered to be a system
>> +profile. Unlike usual profiles, for a system profile, packages
>> +are placed in 'profile' subdirectory."
>> + (let ((profile (if generation
>> + (guix-generation-file profile generation)
>> + profile)))
>> + (if system?
>> + (expand-file-name "profile" profile)
>> + profile)))
>
> It seems you’re calling /run/current-system the system profile, which
> leads to the ‘system?’ Boolean here, but the system profile really is
> /run/current-system/profile.
As we need to work with generations, I use "/var/guix/profiles/system"
instead of a "/run/current-system" link. But you are right, I called it
“system profile”.
I think using "/var/guix/profiles/system/profile" wouldn't help to
remove ‘system?’ boolean. For example:
(guix-packages-profile "/var/guix/profiles/per-user/me/guix-profile" 3)
=> "/var/guix/profiles/per-user/me/guix-profile-3-link"
(guix-packages-profile "/var/guix/profiles/system/profile" 3)
=> "/var/guix/profiles/system/profile-3-link"
The first one is correct, but the second should be:
=> "/var/guix/profiles/system-3-link/profile"
As you can see we need to distinguish system and usual profiles because
packages are placed in different places for them
("system-NN-link/profile" and "usual-NN-link" without "profile" subdir),
that's why I added ‘system?’ argument. I don't see how it can be
avoided.
> I had overlooked it, but wouldn’t it be easier if patch #2 did:
>
> +(defvar guix-system-profile
> + (concat guix-config-state-directory "/profiles/system/profile")
> + "System profile.")
>
> ?
Not really.
Both "/var/guix/profiles/system" (which I called “system profile”) and
"/var/guix/profiles/system/profile" (which I called “packages profile”)
are needed. The former — for finding generations, and the latter — for
finding packages.
I actually need "/var/guix/profiles/system" in the first place, so if
‘guix-system-profile’ is not an appropriate name for this variable, it
should be renamed (what name do you suggest?).
And about name confusion: now I see that “profile” should be used only
for a directory (symlink) with packages. But I always thought that a
directory that has generations can also be named a “profile” (apparently
cannot), especially taking into account ‘profile-generations’ procedure
from (guix profiles) module:
(profile-generations "/var/guix/profiles/system")
That's why ^^^ I called "/var/guix/profiles/system" a system profile.
--
Alex
