Either do:

# Note the braces to force list context on the left hand side
my ($roleid) = autocd::roles->search(rolename => $rolename);
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or

my $role_iter  = autocd::roles->search(rolename => $rolename);
if (!$role_iter->count || !$username){
         return "";
      }
my $roleid = $role_iter->first;
[download]

I'd go for the first option.