Your use vars syntax is broken. The only thing use vars can do is permit a package variable to be spelled without the colons when the current package is the same as the package variable's package.

use vars qw($PATTERN);
$PATTERN = qr(...);
...
...
if ($line =~ $PATTERN) { ... }
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Perhaps you were confusing it with our, which in fairly recent Perl versions, permits a "my"-style declaration, but accesses a package variable rather than a lexical variable.

-- Randal L. Schwartz, Perl hacker
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