See use. You either want the string form of eval, or you want to use 

my $have_module_0 = eval {
    require module_0;
    module_0->import;
    1
};

if (! $have_module_0) {
    require module_1;
    module_1->import;
};

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In reply to Re: conditional 'use' by Corion
in thread conditional 'use' by Anonymous Monk

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