bug#17208: undoing a --roll-back

[Ludovic Courtès]

Eric Bavier <ericbav...@gmail.com> skribis:

> Note that commit b3bb82f1 adds the '--switch-generation' option to
> 'guix package'.

Indeed, I think it answers the original request.
So I’m happily closing the bug.  :-)

Ludo’.