That says that subs in your file cannot participate in lexical closures with variables in the including file. Big packages often have such closures, and subs imported with do will fail. Make sure all subs get all their parameters from arguments passed to them.

My own practice is to only do for subs like those and for a single configuration hashref as the return value for the file when done.

i *should* use "use" or "require", but since i'm doing some quite messy namespace-stuff (plugins, global dbh's, eval-ed strings that call subs, etc.), that would be a major pain in the behind.

Moving this stuff into an external file will not make your code less messy. In fact, I think it will make it more so. Most of the advantage of modules is not having separate files, but having clean interfaces. I'd even venture to say the clean interface is much more important than the separate files.

Here's what I recommend: clean up the interfaces between your core functions and main code, move the core functions into a package, and then think about making a module out of that package. It may seem like a daunting task, but just pick away at it, and, before you know, it will be tolerable and clean.

If you have any questions about how to clean up something specific, you can always post a new question at the Monastery. If there's anything the Monks can do, it's rework a piece of code. :^)

Try only cutting out subroutines or things you can reduce to subroutines. Then load them with BEGIN{require "filename.pl"} and call the subroutines as needed.

Alternatively, disambiguate all the places that you have problems; in the example case, try print INVOICEVIEW (translate(...)."\n").

Why do you think require won't work? The only catch is the "1;" needed at the end of the required file.

--- File: a.pl ---
use DBI;
use MIME::Base64;

BEGIN { require 'b.pl'; }

$VARA = 'a';

local $\ = "\n";

testb();                      # Never imported.

sub testa {
   print("and we're back");
   print($VARB);              # Never imported.
   print(catfile('1', '0'));  # Never imported in this file.
}

--- File: b.pl ---
use File::Spec::Functions;

$VARB = 'b';

sub testb {
   print("magical newlines");           # $\ taking effect.
   print($DBI::VERSION);                # Never used DBI in this file.
   print(encode_base64("Hello World")); # Never imported in this file.
   print($VARA);                        # Never imported.
   testa();                             # Never imported.
}

1;

--- output ---
magical newlines
1.28
SGVsbG8gV29ybGQ=

a
and we're back
b
1/0
[download]

I hope you mean BEGIN {require ...}. Can you show a short but complete example that fails?