I don't think Class::MethodMaker is really the problem.

That use Class::MethodMaker new_with_init   => 'new'; line is equivalent to adding the following subroutine declaration to your package:

    sub new {
      my $class = shift;
      $class = ref $class || $class;
      my $self = {};
      bless $self, $class;
      $self->init(@_);
      $self;
    };
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Perhaps the problem is that Class::DBI provides its own constructor method which it expects you to call?

You might be able to do something more like the following:

        package Foo::DBI;
        use base 'Class::DBI';

        sub new {
          my $self = (shift)->SUPER::new( @_ );
          $self->init();
          return $self;
        }

        sub init {
          my $self->set_db('Main', 'dbi:mysql:database', 'user', 'pass
+word');
        }
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