UPDATE: Code fixed below. The problem was the calls to function() are called in list context, therefore Memoize stores it in a list cache, separate from the scalar cache. Adding an empty string before the function call forces a scalar context.

The segfault went away when I added an unmemoize. But on the second run, it calls the function again instead of using the supposedly cached data in memory.tmp.

#!/usr/bin/perl
use strict;
use warnings;
use diagnostics;

use Memoize qw(memoize unmemoize);
use Memoize::Storable;

my $filename = './memory.tmp';
tie my %cache => 'Memoize::Storable', $filename;

memoize 'function', SCALAR_CACHE => [HASH => \%cache];

print "".function(1), "\n";
print "".function(1), "\n";
print "".function(2), "\n";    # Changed original order
print "".function(1), "\n";
unmemoize 'function';

sub function {
    my $wtf = shift;
    print "I am the $wtf function\n";
    return "anything $wtf";
}
[download]

First run results:

I am the 1 function
anything 1
anything 1
I am the 2 function
anything 2
anything 1
[download]

Second run results:

anything 1
anything 1
anything 2
anything 1
[download]