Ubuntu Version:
Xubuntu 20.04.6 LTS
Desktop Environment (if applicable):
XFCE
Problem Description:
In preparation for upgrading to 22.04, I copied my root partition to another free partition, and updated grub appropriately to dual-boot between the original and copy systems. /home is currently shared. Everything works, apart from one bizarre difference.
I have a locally modified version of xfpm-power-backlight-helper in /usr/local/sbin, and so that it is root-authorized when called on by a brightness change request, I have a policy file
/usr/share/polkit-1/actions/org.xfce.power.local.policy
which copies /usr/share/polkit-1/actions/org.xfce.power.policy but replaces /usr/sbin by /usr/local/sbin. This has worked for the last three years, and still works on the original system.
However, on the copy system, it doesn’t work, in that when I hit the brightness change key, I get an authorization popup requesting permission to execute /usr/local/sbin/xfpm-power-backlight-helper
I am at a loss to see how this can happen.
Relevant System Information:
Not sure what else is relevant.
Screenshots or Error Messages:
What I’ve Tried:
So far, I have tried switching on debug messages in polkitd with G_MESSAGES_DEBUG=all. This shows me that the key difference is that on the original system, the following happens when I hit the brightness key:
** (polkitd:910): DEBUG: 18:06:13.881: system-bus-name::1.70 is inquiring whether unix-process:2859:1290 is authorized for org.xfce.power.backlight-helper
which then succeeds per my policy file, while on the copy system the following happens:
** (polkitd:909): DEBUG: 18:13:06.965: system-bus-name::1.70 is inquiring whether unix-process:2870:1394 is authorized for org.freedesktop.policykit.exec
**
which then fails (as expected since I don’t have a general policy for it) thus:
** (polkitd:909): DEBUG: 18:13:06.966: 0x55d50e455ed0
** (polkitd:909): DEBUG: 18:13:06.966: Checking whether session c2 is active.
** (polkitd:909): DEBUG: 18:13:06.966: Session c2 has UID 28283.
** (polkitd:909): DEBUG: 18:13:06.966: UID 28283 has state active.
** (polkitd:909): DEBUG: 18:13:06.966: subject is in session c2 (local=1 active=1)
** (polkitd:909): DEBUG: 18:13:06.967: challenge (implicit_authorization = auth_admin)
** (polkitd:909): DEBUG: 18:13:06.967:
** (polkitd:909): DEBUG: 18:13:06.967: using authentication agent for challenge
(polkitd:909): GLib-DEBUG: 18:13:06.967: setenv()/putenv() are not thread-safe and should not be used after threads are created
(polkitd:909): GLib-DEBUG: 18:13:06.968: setenv()/putenv() are not thread-safe and should not be used after threads are created
** (polkitd:909): WARNING **: 18:13:06.968: Error parsing identity unix-group:admin: No UNIX group with name admin: Success
(For some reason, I don’t have an admin group, so the warning is not a worry.)
So for some reason the request is different on the copy system than the original system. Where should I go next with the debugging?