  In macroscopic systems, velocity-dependent phenomenological forces $F(v)$ are
used to model friction, feedback devices or self-propulsion. Such forces
usually include a dissipative component which conceals the fast energy
exchanges with a thermostat at the environment temperature $T$, ruled by a
microscopic Hamiltonian $H$. The mapping $(H,T) \to F(v)$ - even if effective
for many purposes - may lead to applications of stochastic thermodynamics where
an $incomplete$ fluctuating entropy production (FEP) is derived. An
enlightening example is offered by recent macroscopic experiments where
dissipation is dominated by solid-on-solid friction, typically modelled through
a deterministic Coulomb force $F(v)$. Through an adaptation of the microscopic
Prandtl-Tomlinson model for friction, we show how the FEP is dominated by the
heat released to the $T$-thermostat, ignored by the macroscopic Coulomb model.
This problem, which haunts several studies in the literature, cannot be cured
by weighing the time-reversed trajectories with a different auxiliary dynamics:
it is only solved by a more accurate stochastic modelling of the thermostat
underlying dissipation.
