I am concerning here a natural question:
$G$ is a finite group, and $N$ is ca characteristic subgroup. Given a single $\varphi\in\mathrm{Aut}(G/N)$, when it can be lifted to an automorphism of $G$?
The problem in general seems difficult, and it has raised four years before in MathOverflow (see this).
Question: for which classes (or cases) of groups $G$ or $N$, this question has been studied?