That doesn't do what you expect. The second use Foo::Bar gets executed first, and it gets executed unconditionally.

Why would you want to fallback to the same module anyway? That's the same as not putting a version in the first place! If you wanted to fallback to a different module, the following will do: 

BEGIN {
   my $module = 'Foo::Bar';
   require Foo::Bar;

   eval { Foo::Bar->VERSION(5.01) };
   if ($@) {
      warn(...);
      $module = 'Foo::Baz';
      require Foo::Baz;
   }

   import $module qw( ... );
}

[download]

VERSION is documented in UNIVERSAL.

In reply to Re^2: BEGIN and compile-time by ikegami
in thread BEGIN and compile-time by jbert

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