simpleclient: Preserve the "#auto" install marker through local depen…

[AlexB7]

Related: linuxmint/mintupdate#938 and linuxmint/mintupdate#1078

Summary

Companion fix to a mintupdate change (https://github.com/linuxmint/mintupdate, branch: autoremove-kernel-fix) that fixes apt autoremove never cleaning up old kernels installed via mintupdate. PR linuxmint/mintupdate#1081

Root cause

aptworker._mark_packages_for_installation() already supports an opt-in convention for callers: a package name suffixed with #auto (e.g. "linux-image-6.17.0-41-generic#auto") is installed with from_user=False, i.e. recorded as automatically installed rather than manually installed. This is what lets a caller install a specific package by name while still leaving it eligible for apt autoremove later, matching how apt would treat it if it had been pulled in as a dependency instead.

SimpleAPTClient.install_packages() undermines this. Before handing the package list to the worker over D-Bus, it does a local apt.Cache() dependency resolution pass to discover any additional packages a request will pull in (e.g. a kernel image pulled in by a meta package upgrade), and appends their bare names to the same packages list:

for pkg in changes:
    if pkg.marked_install and pkg.name not in packages:
        packages.append(pkg.name)

None of these names carry the #auto suffix, so every package in the flattened list — both the ones the caller explicitly asked for and the ones only pulled in as a dependency — ends up marked manually installed by the worker. This defeats the purpose of the #auto convention entirely: even a caller that tags its own request with #auto gets nothing, since the local resolver strips out whatever wasn't an exact literal package name in the original list in the first place, and anything it discovers is re-added without the tag.

History

The flattening step was introduced in 18d255f ("simpleclient: Use python-apt resolver when installing pkgs", 2024-09-11), days before mintupdate 7.0.0 switched its installs from synaptic to aptkit. The combination is what regressed kernel autoremoval for mintupdate users: under synaptic (and under aptkit without the flattening), dependency packages were marked automatically installed by the resolver, so superseded kernels remained autoremovable. The "#auto" convention itself predates the fork - it was inherited from aptdaemon in the initial aptkit import (April 2022) and validated at the D-Bus boundary all along, but no client ever used it.

Fix

• Compute requested_names by stripping any #auto suffix before doing the local apt.Cache() lookups (apt itself doesn't know about the suffix convention), so callers can pass pre-tagged names through install_packages() without breaking the resolution step.
• Newly-discovered dependency packages (present in cache.get_changes() but not in the caller's original request) are now tagged #auto themselves before being appended, since by definition they were resolved rather than explicitly requested — matching what a normal apt install/apt upgrade would leave them as.

Behavior change for all SimpleAPTClient consumers

Note that the second part affects every caller of SimpleAPTClient.install_packages() (mintinstall, driver manager, ...), not just mintupdate: dependency packages pulled in alongside a requested package are now recorded as automatically installed, where previously the flattening step left them manually installed. This moves aptkit toward standard apt semantics — after a plain apt install foo, foo's dependencies are marked auto and become autoremovable once nothing needs them — so e.g. libraries installed alongside an application can now be reclaimed by apt autoremove after the application is removed, instead of lingering forever. Callers that genuinely want a dependency pinned as manual can still request it explicitly by name.

Testing

Manually tested as part of the mintupdate branch above: with this change plus the mintupdate-side tagging, apt-mark showauto shows newly-installed kernel packages as automatic (previously all showed as manual), and apt-get autoremove --dry-run / apt autoremove correctly identify and reclaim superseded kernel packages while leaving the running kernel untouched.

No test suite exists in this repo to extend.

Claude Fable 5 was used to fix these issues.

[randomnoise]

Unfortunately, exact duplicate of

• simpleclient.py: Use #auto tag on dependencies when use_apt_resolver is True. #14

[AlexB7]

Unfortunately, exact duplicate of

• simpleclient.py: Use #auto tag on dependencies when use_apt_resolver is True. #14

Yes but with some more logic and it's needed for linuxmint/mintupdate#1081.