vanishing spaces

[Ray Andrews <rayandrews@xxxxxxxxxxx>]

    aptitude columnizes its output nicely: (cut down here to avoid 
wrapping):

% aptitude search '~i?name(nvidia)'
i A glx-alternative-nvidia                  - allows the selection of 
NVIDIA i A libegl-nvidia-tesla-470-0               - NVIDIA binary EGL 
library
i A libgl1-nvidia-tesla-470-glvnd-glx       - NVIDIA binary OpenGL/GLX
i A libgles-nvidia-tesla-470-1              - NVIDIA binary OpenGL|ES 1.x

    ... I have reason to capture the output of several versions of 
aptitude searches into a variable. I hope 'eval' is the right way:

output=$( eval $* )  # Save output to an array variable.

    ... where: '$*' ... is the command string that's been put together 
elsewhere.

print -l $output
i A glx-alternative-nvidia - allows the selection of NVIDIA as GLX provider
i A libegl-nvidia-tesla-470-0 - NVIDIA binary EGL library (Tesla 470 
version)
i A libgl1-nvidia-tesla-470-glvnd-glx - NVIDIA binary OpenGL/GLX library

    ... the nice columns disappear. However:

eval $*

    ... shows it with columns intact so eval itself is not the issue 
it's somewhere in the capture of the variable.  How can I fix that?  I'm 
used to doing battle with splitting issues but this seems different.  
'typeset -p' shows me nothing useful.  Is this one of those things were 
zsh is helpfully removing an empty element?  Somehow the padding spaces 
are their own separate element and since empty, removed?  That's my only 
guess.  I've tried a dozen variations on quoting with no luck. I know 
how to preserve empty lines, but that doesn't work here.