[lunar] Hundreds of calls to lsb_release from apt-check

[Andreas Hasenack]

I'm not entirely sure the bug is in update-notifier, but let's start here.

In lunar, this script is triggering hundreds of calls to "lsb_release -c -s":

# time /usr/lib/update-notifier/apt-check --human-readable
221 updates can be applied immediately.
To see these additional updates run: apt list --upgradable

real 0m7.628s
user 0m5.955s
sys 0m1.115s

Running execsnoop on the host, and apt-check in a lunar lxd container, execsnoop records 222 lsb_release calls.

The exact lsb_release call comes from get_dist() from https://git.launchpad.net/ubuntu/+source/update-manager/tree/UpdateManager/Core/utils.py#n210

Here is a pastebin: https://paste.ubuntu.com/p/FKzBZ3k4nZ/

apt-check's pid is 352917 (line 39 of paste), and that's the PPID of every lsb_release call following that

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Renan Rodrigo (renanrodrigo)]

It happens because UpdateManager.Core.UpdateList.UpdateList is being instantiated once per update (so, I see two calls to lsb_release here because I have only 2 upgrades available).

Neverthless it can be improved; I am sending a patch that reduces it to zero calls (:

[Renan Rodrigo (renanrodrigo)]

If the team wants to accept the change, we will need a SRU for https://bugs.launchpad.net/ubuntu/+source/update-notifier/+bug/2002168 anyway - and this patch can be included, as it affects all the other releases as well.