Take a look at the embedded package in the OP code.

I'm saying that coded this way:

#! perl -sl
use strict;
use warnings;

X::test();

{
    package X;

    $FRED = 'fred';

    sub test {
        print 'This is package:', __PACKAGE__;
    }

    1;
}
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The strict & warnings affect that embedded package:

C:\test>perl -c test.pl
Global symbol "$FRED" requires explicit package name at test.pl line 1
+0.
test.pl had compilation errors.
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But coded this way:

#! perl -sl

{
    package X;

    $FRED = 'fred';

    sub test {
        print 'This is package:', __PACKAGE__;
    }

    1;
}

use strict;
use warnings;

X::test();
[download]

They do not:

C:\test>perl -c test.pl
test.pl syntax OK
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