... the variable would be in a different package ...
... I don't need to put  once in its own package; I can simply have it in my current package, and this would make your solution indeed feasible.
I'm still a bit confused, and I suspect we may be posting at cross-purposes.

What I wanted to illustrate is that a package variable may be declared in any package at any time (with either use vars or our), and may then be accessed from any other package at any (executionally subsequent) time. 

>perl -wMstrict -le
"package Some::Package;
   our $scalar = 'foo';
 package Some::Other::Package;
   print $Some::Package::scalar;
   print 'current package is ', eval { scalar caller };
"
foo
current package is Some::Other::Package

[download]
Update: Oops... Forgot to include example code.

In reply to Re^3: Why do I get a "used only once" warning here? by AnomalousMonk
in thread Why do I get a "used only once" warning here? by rovf

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.