Lagrangian formalism and dissipative systems [duplicate]

Why the central concepts of classical mechanics, viz. Lagrangian and Hamiltonian formalisms cannot address constraint forces like friction and others in dissipative systems?

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All the kinds of constraints you can have in your, say, lagrangian system must satisfy a relation called ideality of the constraint, which takes into account the so called virtual displacements, indeed it states: $$\sum_i\bar{N}_i\cdot\delta \bar{r}_i=0.$$ This is a statement you use for building your configuration space.