VERSION_FROM in ExtUtils::MakeMaker scans a file for the first line matching: 

/([\$*])(([\w\:\']*)\bVERSION)\b.*\=/

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Then evals it, using the result as the version.

This snippet does it from the command line to check that everything works as you expect. 

perl -nle 'if(/([\$*])(([\w\:'\'']*)\bVERSION)\b.*\=/){ eval $_; print
+ "$ARGV:\n$@$_\n\$$2 = $$2\n";close ARGV; undef $VERSION}' a b c d

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Sample output: 
a:
        (our $VERSION = '3.0')
$VERSION = 3.0

b:
my $VERSION = 2.0;
$VERSION = 

c:
Undefined subroutine &main::qv called at (eval 3) line 1, <> line 2.
our $VERSION = qv(1.0);
$VERSION = 

d:
use version; our $VERSION = qv(1.0);
$VERSION = v1.0.0

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