Раньше я делал так:

% cat cleanup-kernels
#clear APT::NeverAutoRemove;

# apt -c=~/cleanup-kernels --purge autoremove

И всё работало, но теперь перестало.

% apt-config dump | grep -i autore
APT::AutoRemove "";
APT::AutoRemove::RecommendsImportant "false"; APT::AutoRemove::SuggestsImportant "false";
APT::NeverAutoRemove "";
APT::NeverAutoRemove:: "^linux-image.*";
APT::NeverAutoRemove:: "^linux-headers.*";
APT::NeverAutoRemove:: "^linux-kbuild.*";
APT::NeverAutoRemove:: "^linux-doc.*";

% apt-config -c=~/cleanup-kernels dump | grep -i autore
APT::AutoRemove "";
APT::AutoRemove::RecommendsImportant "false"; APT::AutoRemove::SuggestsImportant "false";
APT::NeverAutoRemove "";

% apt-mark showauto linux-image-5.10.0-5-amd64
linux-image-5.10.0-5-amd64

% aptitude why linux-image-5.10.0-5-amd64
Automatically installed, current version 5.10.26-1, priority optional
No dependencies require to install linux-image-5.10.0-5-amd64


--
sergio.

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

Сбрасывать ещё и VersionedKernelPackages:

% cat cleanup-kernels
#clear APT::NeverAutoRemove;
#clear APT::VersionedKernelPackages;

--
sergio.

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)