Re: Creating user profiles

[ludo@gnu.org (Ludovic Courtès)]

Andreas Enge <andreas@enge.fr> skribis:

> I simply applied the patch, and it seems to be part of the solution.
> Upon a first run of "guix-package --list-available", I obtained the error 
> message inviting me to create the directory, which I did. The next call 
> succeeded. But now $HOME/.guix-profile points to the non-existing 
> /usr/local/guix-git/var/nix/profiles/per-user/privat/guix-profile, and I 
> get the error:

[...]

>    ?: 0 [symlink "/usr/local/guix-git/var/nix/profiles/per-
> user/privat/guix-profile" ...]
>
> ERROR: In procedure symlink:
> ERROR: In procedure symlink: File exists

Aah, I see.  That’s because it did (file-exists? ".guix-profile"), but
this uses stat(2).  So here, because .guix-profile was a dangling
symlink, it returned #f, even though the symlink actually existed.  I
fixed it using ‘lstat’ instead.

[...]

> I would suggest the following: Before making the $HOME/.guix-profile 
> symlink, check for the guix-profile symlink in the per-user profile 
> directory. If it does not exist, create it as a link to the empty user 
> environment. So there will always be guix-profile-1-link linking to the 
> empty directory, which might also be useful for roll back (never delete 
> this first empty environment).

Having this empty user environment on disk should not be needed because
internally, ‘profile-manifests’ explicitly checks whether the profile
exists, and returns an empty manifest if it doesn’t.

So I’m committing the patch, minus the above bug.

Thanks for the very quick feedback!

Ludo’.