Control: found -1 2.9.1

On 2023-11-01 21:53:26 +0100, Vincent Lefevre wrote:

Package: apt
Version: 2.6.1
Severity: normal

I've installed several -perl packages with "apt install", including libio-async-perl, and libtest-fatal-perl:amd64 was automatically
installed as a dependency:

Start-Date: 2023-11-01 21:03:35
Commandline: apt install libio-async-perl
Install: libdevel-mat-dumper-perl:amd64 (0.46-1+b1, automatic), libio-async-perl:amd64 (0.802-1), libtest-fatal-perl:amd64 (0.017-1, automatic), libtest-metrics-any-perl:amd64 (0.01-2, automatic), libsereal-perl:amd64 (5.003-1, automatic), libmetrics-

any-perl:amd64 (0.09-1, automatic), libstruct-dumb-perl:amd64 (0.14-1, automatic), libtest-refcount-perl:amd64 (0.10-4, automatic), libasync-mergepoint-perl:amd64 (0.04-4, automatic)

End-Date: 2023-11-01 21:03:39

A bit later, I found that this was not needed, so that I removed the
packages and also did a "apt autoremove --purge". Now, this command
says:

root@qaa:~# apt autoremove --purge
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.

but while libtest-fatal-perl:amd64 (from /var/log/apt/history.log
above) isn't installed, libtest-fatal-perl still is:

root@qaa:~# dpkg -s libtest-fatal-perl:amd64
dpkg-query: package 'libtest-fatal-perl' is not installed and no information is available
Use dpkg --info (= dpkg-deb --info) to examine archive files.

root@qaa:~# dpkg -s libtest-fatal-perl
Package: libtest-fatal-perl
Status: install ok installed
Priority: optional
Section: perl
Installed-Size: 43
Maintainer: Debian Perl Group <pkg-perl-maintainers@lists.alioth.debian.org> Architecture: all
Multi-Arch: foreign
Version: 0.017-1
Depends: perl:any, libtry-tiny-perl

Well, this isn't really the right explanation. This is due to an
output bug in apt, which should have output "libtest-fatal-perl:all"
instead of "libtest-fatal-perl:amd64".

So "apt autoremove" forgot it.

And I can reproduce the issue on another machine:

disset:~> apt-mark showauto | grep libtest-fatal-perl
libtest-fatal-perl

disset:~> apt autoremove -s
NOTE: This is only a simulation!
apt needs root privileges for real execution.
Keep also in mind that locking is deactivated,
so don't depend on the relevance to the real current situation!
Summary:
Upgrading: 0, Installing: 0, Removing: 0, Not Upgrading: 18

disset:~> aptitude why libtest-fatal-perl
i libmastodon-client-perl Depends libdatetime-perl
i A libdatetime-perl Depends libspecio-perl
i A libspecio-perl Suggests libtest-fatal-perl

disset:~> aptitude remove -s libtest-fatal-perl
The following packages will be REMOVED:
libtest-fatal-perl
0 packages upgraded, 0 newly installed, 1 to remove and 18 not upgraded.
Need to get 0 B of archives. After unpacking 44.0 kB will be freed.
Would download/install/remove packages.

So, there's only a "Suggests", and note that I do not install
"Suggests" by default.

The only place this package appears in the history is

Start-Date: 2024-01-06 02:53:49
Commandline: apt install libhtml-gumbo-perl libidn-dev libimage-exiftool-perl libipc-run-perl liblinux-inotify2-perl libmastodon-client-perl
Install: libdevel-mat-dumper-perl:amd64 (0.47-1, automatic), libclass-load-perl:amd64 (0.25-2, automatic), libsafe-isa-perl:amd64 (1.000010-1, automatic), libmastodon-client-perl:amd64 (0.017-2), libhash-multivalue-perl:amd64 (0.16-3, automatic),
libimage-base-bundle-perl:amd64 (1.0.7-3.5, automatic), libio-async-perl:amd64 (0.802-2, automatic), libtest-fatal-perl:amd64 (0.017-1, automatic), pkgconf:amd64 (1.8.1-1, automatic), libtest-metrics-any-perl:amd64 (0.01-2, automatic), libcompress-raw-
lzma-perl:amd64 (2.206-2, automatic), libsereal-perl:amd64 (5.004-1, automatic), libio-async-ssl-perl:amd64 (0.25-1, automatic), libidn-dev:amd64 (1.41-1), libhtml-gumbo-perl:amd64 (0.18-3+b2), libimage-info-perl:amd64 (1.44-1, automatic), libimage-
exiftool-perl:amd64 (12.67+dfsg-1), libmetrics-any-perl:amd64 (0.10-1, automatic), libcompress-bzip2-perl:amd64 (2.28-1+b3, automatic), pkg-config:amd64 (1.8.1-1, automatic), libfuture-perl:amd64 (0.50-1, automatic), liblinux-inotify2-perl:amd64 (1:2.3-2)
, libstruct-dumb-perl:amd64 (0.14-1, automatic), pkgconf-bin:amd64 (1.8.1-1, automatic), libtypes-path-tiny-perl:amd64 (0.006-2, automatic), libtest-refcount-perl:amd64 (0.10-4, automatic), libpkgconf3:amd64 (1.8.1-1, automatic), libasync-mergepoint-perl:
amd64 (0.04-4, automatic), libhttp-thin-perl:amd64 (0.006-2, automatic), libnet-async-http-perl:amd64 (0.49-1, automatic), librole-eventemitter-perl:amd64 (0.003-2, automatic), libfuture-xs-perl:amd64 (0.12-1, automatic), libfuture-io-perl:amd64 (0.15-1,
automatic)
End-Date: 2024-01-06 02:53:54

I suppose that libtest-fatal-perl was automatically installed
because libio-async-perl 0.802-2 recommended it. But this
"Recommends" was removed in libio-async-perl 0.803-1, which
is currently installed on this machine.

In the "Reverse Depends" listed by "apt-cache showpkg libtest-fatal-perl",
only 2 packages are installed (libspecio-perl and libio-async-perl),
but this is a "Suggests" in both cases.

--
Vincent Lefèvre <vincent@vinc17.net> - Web: <https://www.vinc17.net/>
100% accessible validated (X)HTML - Blog: <https://www.vinc17.net/blog/>
Work: CR INRIA - computer arithmetic / AriC project (LIP, ENS-Lyon)

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On 2024-04-21 12:03:05 +0200, David Kalnischkies wrote:

On Sun, Apr 21, 2024 at 03:35:28AM +0200, Vincent Lefevre wrote:

root@qaa:~# dpkg -s libtest-fatal-perl:amd64
dpkg-query: package 'libtest-fatal-perl' is not installed and no information is available
Use dpkg --info (= dpkg-deb --info) to examine archive files.

[...]

Well, this isn't really the right explanation. This is due to an
output bug in apt, which should have output "libtest-fatal-perl:all" instead of "libtest-fatal-perl:amd64".

That might be your preference (now), but it would be wrong in terms of
apt and I am sure if you think a bit more about it you will agree:

A package is not arch:all. People say that all the time, but only
because they mean that "this version of the package is arch:all" as we
tend to talk about a *.deb file as a package and that contains
a specific version.

If apt were to display "libtest-fatal-perl:all" it would mean that if
that package becomes arch:any in the next version apt would need
to show "removing: libtest-fatal-perl:all" and "new install: libtest-fatal-perl:amd64" instead of as an "upgrade" among many other
very annoying things around architectures.

So, for apt, "libtest-fatal-perl:all" is treated like "libtest-fatal-perl:native" aka "libtest-fatal-perl:amd64" for you, so
that if a binary package is arch:any or arch:all is an implementation
detail for a user – as it should be – as that changes over time.
The native architecture does not change as often, if at all.

So, in other words, for apt a "package" is usually a set of versions
which can have different architectures, while for dpkg a package is
a single version (except if it is not, like in that same arch:all to
arch:any flip; but users don't speak to dpkg that often and especially
not in that moment. apt does for them…).

In a way, you could complain that dpkg is so anal about the arch
instead, but in its own world and context, it makes sense.

But here, "apt install ..." outputs libtest-fatal-perl:amd64, which is
a particular version of this package. And just after the installation,
"dpkg -s ..." refers to exactly the same version. So one should expect
that both tools use a common name to designate the package.

So, there's only a "Suggests", and note that I do not install
"Suggests" by default.

While you don't install Suggests via `APT::Install-Suggests` which is
`false` by default, that has no bearing on the autoremoval.

Controlling autoremoval behaviour is `APT::AutoRemove::SuggestsImportant` which defaults to `true` as the autoremover could potentially break some usecase for you that the suggests enabled and you have grown attached to
even through the suggests was once installed for another reason.

OK, I had actually that on my old machines, but for some reason,
I didn't remember that and didn't notice that this was missing on
new machines (and there was a bug in my script that checked the
consistency of the config between machines).

But the fact that this is a hidden setting did not help, i.e. it is
not mentioned in the documentation (apt(8), apt-get(8), apt.conf(5), apt-config(8) man pages, APT User's Guide), while the description of
"apt autoremove" is misleading ("dependencies" is used twice in the
same sentence with 2 different meanings!).

--
Vincent Lefèvre <vincent@vinc17.net> - Web: <https://www.vinc17.net/>
100% accessible validated (X)HTML - Blog: <https://www.vinc17.net/blog/>
Work: CR INRIA - computer arithmetic / AriC project (LIP, ENS-Lyon)

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On 2024-04-22 03:19:36 +0200, Vincent Lefevre wrote:

On 2024-04-21 12:03:05 +0200, David Kalnischkies wrote:

Controlling autoremoval behaviour is `APT::AutoRemove::SuggestsImportant` which defaults to `true` as the autoremover could potentially break some usecase for you that the suggests enabled and you have grown attached to even through the suggests was once installed for another reason.

OK, I had actually that on my old machines, but for some reason,
I didn't remember that and didn't notice that this was missing on
new machines (and there was a bug in my script that checked the
consistency of the config between machines).

I meant that I had

APT::AutoRemove::SuggestsImportant "false";

in a config file on old machines (added 6 years ago), but this
file was missing on the new machines, and I did not remember of
the existence of this setting because:

But the fact that this is a hidden setting did not help, i.e. it is
not mentioned in the documentation (apt(8), apt-get(8), apt.conf(5), apt-config(8) man pages, APT User's Guide), while the description of
"apt autoremove" is misleading ("dependencies" is used twice in the
same sentence with 2 different meanings!).

--
Vincent Lefèvre <vincent@vinc17.net> - Web: <https://www.vinc17.net/>
100% accessible validated (X)HTML - Blog: <https://www.vinc17.net/blog/>
Work: CR INRIA - computer arithmetic / AriC project (LIP, ENS-Lyon)

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