Removal of kdump-tools does not remove crashkernel reservation

[Jürg Häfliger]

Apparently kdump is enabled automatically nowadays. However, after removing the kdump-tools package, the kernel commandline still contains the crashkernel=... argument.

I expect a package purge to undo all the custom things it did on installation.

[Jürg Häfliger (juergh)]

$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu Plucky Puffin (development branch)
Release: 25.04
Codename: plucky

$ sudo apt purge kdump-tools
The following packages were automatically installed and are no longer required:
  crash kexec-tools libsnappy1v5 libtracker-sparql-3.0-0 makedumpfile tracker tracker-miner-fs
Use 'sudo apt autoremove' to remove them.

REMOVING:
  kdump-tools*

<snip>

(Reading database ... 195489 files and directories currently installed.)
Purging configuration files for kdump-tools (1:1.10.5ubuntu2) ...

$ sudo grep crash /boot/grub/grub.cfg
 linux /boot/vmlinuz-6.14.0-7-generic root=UUID=93104e11-c6a6-4386-8450-4bd657a60072 ro clk_ignore_unused pd_ignore_unused arm64.nopauth quiet splash crashkernel=2G-4G:320M,4G-32G:512M,32G-64G:1024M,64G-128G:2048M,128G-:4096M $vt_handoff
  linux /boot/vmlinuz-6.14.0-7-generic root=UUID=93104e11-c6a6-4386-8450-4bd657a60072 ro clk_ignore_unused pd_ignore_unused arm64.nopauth quiet splash crashkernel=2G-4G:320M,4G-32G:512M,32G-64G:1024M,64G-128G:2048M,128G-:4096M $vt_handoff
  linux /boot/vmlinuz-6.12.0-16-generic root=UUID=93104e11-c6a6-4386-8450-4bd657a60072 ro clk_ignore_unused pd_ignore_unused arm64.nopauth quiet splash crashkernel=2G-4G:320M,4G-32G:512M,32G-64G:1024M,64G-128G:2048M,128G-:4096M $vt_handoff

[Jürg Häfliger (juergh)]

It looks like this is just missing an `update-grub` after package removal.