I've heard rumors that Perl 6 will solve this problem. Personally I don't think it's going to be all that helpful. New versions are released for a reason - leaving old code using old versions of their dependencies is only going to get you so far. Your example is a good one - if XYZ v1 and v2 are both being used to access the same physical database then you've likely got a problem that Perl alone supporting multiple version loading can't solve.

I haven't had a chance to try it yet, but I thought Erlang's facility for running multiple versions of code long enough to do a seemless cut-over sounded smart. Since everything in Erlang is a networked server the system starts up the new version and starts sending all new requests to it. Once the old version is done handling any lingering requests it gets shutdown.

-sam

In reply to Re^3: How can I (safely) use packages of the same name but different versions? by samtregar
in thread How can I (safely) use packages of the same name but different versions? by xevian

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.