Am Sonntag, 13. Januar 2013 schrieb Ludovic Courtès:
> Right, good point.  (Apparently Nix’s manual doesn’t mention it either.)
> So here’s what I would do:

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:

Backtrace:
In ice-9/boot-9.scm:
 149: 9 [catch #t #<catch-closure 14e29c0> ...]
 157: 8 [#<procedure 147e0f0 ()>]
In unknown file:
   ?: 7 [catch-closure]
In ice-9/boot-9.scm:
  63: 6 [call-with-prompt prompt0 ...]
In ice-9/eval.scm:
 407: 5 [eval # #]
In unknown file:
   ?: 4 [call-with-input-string "(apply (module-ref (resolve-interface 
'(guix-package)) 'guix-package) (cdr (command-line)))" ...]
In ice-9/command-line.scm:
 174: 3 [#<procedure 1415500 at ice-9/command-line.scm:169:3 (port)> 
#<input: string 12a51a0>]
In unknown file:
   ?: 2 [eval (apply (module-ref # #) (cdr #)) #<directory (guile-user) 
14e4d80>]
In /usr/local/bin/guix-package:
 467: 1 [guix-package "--list-available"]
In unknown file:
   ?: 0 [symlink "/usr/local/guix-git/var/nix/profiles/per-
user/privat/guix-profile" ...]

ERROR: In procedure symlink:
ERROR: In procedure symlink: File exists

The problem is that the call to "guix-package --list-available" does not 
actually create anything in the per-user profile directory.

After deleting $HOME/.guix-profile again and running "guix-package -i 
hello", the per-user profile directory contains a symbolic link guix-
profile-1-link to a user environment in the nix store, and a symbolic link 
guix-profile to guix-profile-1-link, and $HOME/.guix-profile points to the 
right thing. Then "guix-package --list-available" succeeds.

Now I can even remove the hello package, since then the per-user profile 
directory contains a link to the empty user environment in the nix store.

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).

Andreas