The documentation about the eval function mentions nothing of the sort. Clearly having compiler warnings for every instance of eval seems ridiculous, but I feel that something about this needs to be in the main documentation about the eval function.

Patches welcome.

Your example is actually working with two completely different scopes. Consider this:

use temp1;
use warnings;
use strict;

temp1::init();

use temp1;
use warnings;
use strict;

temp1::init();

print "Calling work1: " . temp1::work1( '$var = 3' ) . "\n";
print "Calling work2: " . temp1::work2( '$var++' ) . "\n";
print "Calling work3: " . temp1::work3( '$var++' ) . "\n";
print "Work3 again:   " . temp1::work3( '++$var' ) . "\n";
print "Calling work4: " . temp1::work4( '$var++' ) . "\n";
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package temp1;
use strict;
use warnings;

my $var;

sub init { $var = 101 }
sub work1 { return eval shift; }
sub work2 { my $foo = shift; return eval $foo; $var }
sub work3 { return eval $_[0]; }
sub work4 { eval $var; }

1;
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The output is:

Calling work1: 3
Calling work2: 101
Calling work3: 3
Work3 again:   5
Calling work4: 102
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