I did a bit of cleanup. I did not follow tye's suggestion because from both my reading of p5p and from my own tests, using "/" as a directory separator works portably. It might not look pretty, but it works.

The biggest improvement is that you automatically are going to inherit correctly. My new test script is:

#! /usr/bin/perl
# See comments in Versioning about warnings
use strict;
require versioned_module;
tst(0);
tst(1);
tst(0);
tst(1);

sub tst {
  $ENV{IS_PROD} = shift;
  import versioned_module("report_version");
  report_version("Procedural");
  report_version versioned_module("OO");
}
[download]

and the versioned modules look like:

use vars qw(@EXPORT_OK);
@EXPORT_OK = qw(report_version);

sub report_version {
  my $arg = pop();
  my $ver = __PACKAGE__;
  print "Got version $ver through $arg interface\n";
}
[download]