On Wed 05 Aug 2020 at 22:53:26 (+0200), Urs Thuermann wrote:
> Should this be considered a bug? Shouldn't 'aptitude why' show the
> packages that depend on it?
Why not read the man page:
Note
aptitude why does not perform full dependency
resolution; it only displays direct relationships
between packages. For instance, if A requires B, C
requires D, and B and C conflict, “aptitude why-not D”
will not produce the answer “A depends on B, B
conflicts with C, and D depends on C”.
By default aptitude outputs only the “most installed,
strongest, tightest, shortest” dependency chain. That is,
it looks for a chain that only contains packages which are
installed or will be installed; it looks for the strongest
possible dependencies under that restriction; it looks for
chains that avoid ORed dependencies and Provides; and it
looks for the shortest dependency chain meeting those
criteria. These rules are progressively weakened until a
match is found.
If the verbosity level is 1 or more, then all the
explanations aptitude can find will be displayed, in
inverse order of relevance. If the verbosity level is 2 or
more, a truly excessive amount of debugging information
will be printed to standard output.
> # aptitude why libpam-systemd
> i systemd Recommends libpam-systemd
> #
This looks like you used the default. You will probably need to pipe
the output through less:
$ aptitude why libpam-systemd | wc
1 4 35
$ aptitude -v why libpam-systemd | wc
26449 130410 1657367
$ aptitude -v -v why libpam-systemd | wc
4317784 23501088 268859202
$
BTW, with -s you don't need to do this sort of analysis as root.
$ aptitude -s purge libpam-systemd
The following packages will be REMOVED:
libpam-systemd{p}
0 packages upgraded, 0 newly installed, 1 to remove and 0 not upgraded.
Need to get 0 B of archives. After unpacking 406 kB will be freed.
The following packages have unmet dependencies:
udisks2 : Depends: libpam-systemd but it is not going to be installed
policykit-1 : Depends: libpam-systemd but it is not going to be installed
dbus-user-session : Depends: libpam-systemd but it is not going to be installed
The following actions will resolve these dependencies:
Remove the following packages:
1) colord [1.4.3-4 (now, stable)]
2) dbus-user-session [1.12.20-0+deb10u1 (now, stable)]
3) policykit-1 [0.105-25 (now, stable)]
4) udisks2 [2.8.1-4 (now, stable)]
Install the following packages:
5) dbus-x11 [1.12.20-0+deb10u1 (stable)]
Leave the following dependencies unresolved:
6) cups recommends colord
7) cups-daemon recommends colord
8) cups-filters recommends colord
9) hplip recommends policykit-1
10) needrestart recommends libpam-systemd | sysvinit-core
11) openssh-server recommends default-logind | logind | libpam-systemd
12) systemd recommends libpam-systemd
13) udisks2 recommends policykit-1
14) xserver-xorg-core recommends libpam-systemd
Accept this solution? [Y/n/q/?] q
Abandoning all efforts to resolve these dependencies.
Abort.
$
Cheers,
David.
