use Carp qw( croak );

sub require_exact_ver(*$) {
   my ($pkg, $desired_ver) = @_;

   {
      my $ver = $pkg->VERSION;
      return 1 if defined($ver)
               && $ver == $desired_ver;
   }

   my $file = $pkg;
   $file =~ s{::}{/}g;
   $file .= '.pm';

   foreach $inc (@INC) {
      delete $INC{$file};
      local @INC = $inc;
      eval { require $file }
         or next;

      my $ver = $pkg->VERSION;
      return 1 if defined($ver)
               && $ver == $desired_ver;
   }

   delete $INC{$file};
   croak("Unable to load $pkg version $desired_ver");
}