undoing a --roll-back

[Yagnesh Raghava Yakkala]

Hello all,

I am trying to understand rollback feature. I have five generations in the
package history. As I operated roll-back command, my "current" generation sets
to 3 from 4 (shell log pasted below). Now how can I return to 4. More general, 
can I
go to a desired generation by giving number?  say "guix package 
--goto-generation #"

Thanks.

╭─────
│sealion:~
│$ guix package --roll-back
│switching from generation 4 to 3
│nothing to be done
│✗ sealion:~
│$ guix package --fallback
│nothing to be done
│sealion:~
│$ guix package --list-generations
│Generation 1   Apr 06 2014 20:43:55
│  autoconf     2.69    out     
/gnu/store/j1jlnidgsl91vka52faxd8gg7785ps2h-autoconf-2.69
│
│Generation 2   Apr 06 2014 21:12:09
│  autoconf     2.69    out     
/gnu/store/j1jlnidgsl91vka52faxd8gg7785ps2h-autoconf-2.69
│  hello        2.9     out     
/gnu/store/5k0dr40p8404sgjx9w7vbb9vdcp6kzsl-hello-2.9
│
│Generation 3   Apr 06 2014 21:13:38    (current)
│  autoconf     2.69    out     
/gnu/store/j1jlnidgsl91vka52faxd8gg7785ps2h-autoconf-2.69
│  hello        2.9     out     
/gnu/store/5k0dr40p8404sgjx9w7vbb9vdcp6kzsl-hello-2.9
│  automake     1.14.1  out     
/gnu/store/nnljzxzsjf5wrr28j2zy3k6y71a8y28p-automake-1.14.1
│
│Generation 4   Apr 06 2014 22:26:05
│  autoconf     2.69    out     
/gnu/store/j1jlnidgsl91vka52faxd8gg7785ps2h-autoconf-2.69
│  hello        2.9     out     
/gnu/store/5k0dr40p8404sgjx9w7vbb9vdcp6kzsl-hello-2.9
│  automake     1.14.1  out     
/gnu/store/nnljzxzsjf5wrr28j2zy3k6y71a8y28p-automake-1.14.1
│  emacs        24.3    out     
/gnu/store/5aqsf21m86qf03jj8rc6bvq9v0xnlws5-emacs-24.3
│
│Generation 5   Apr 07 2014 02:26:17
│  autoconf     2.69    out     
/gnu/store/j1jlnidgsl91vka52faxd8gg7785ps2h-autoconf-2.69
│  hello        2.9     out     
/gnu/store/5k0dr40p8404sgjx9w7vbb9vdcp6kzsl-hello-2.9
│  automake     1.14.1  out     
/gnu/store/nnljzxzsjf5wrr28j2zy3k6y71a8y28p-automake-1.14.1
╰─────

-- 
ఎందరో మహానుభావులు అందరికి వందనములు.
YYR