IgnoreGroup is ignored for AUR packages

[otaj]

Hi,

Installed packages from AUR which have a group specifically set and the group is listed in IgnoreGroup in /etc/pacman.conf gets updated by pikaur.

For example, package librealsense was recently updated. Expected behavior was to respect IgnoreGroup set in /etc/pacman.conf and potentially warn about holding back a package

otaj@otaj-ntb: cat /etc/pacman.conf
...
# Pacman won't upgrade packages listed in IgnorePkg and members of IgnoreGroup
# IgnorePkg   = 
IgnoreGroup = mods
...

otaj@otaj-ntb: pikaur -Qg mods                                                                                     
mods cgal
mods flann
mods librealsense
mods linux-zen
mods linux-zen-docs
mods linux-zen-headers
mods python-pyrealsense2
mods python-pytorch-cuda
mods python-tensorflow-cuda
mods tensorflow-cuda

otaj@otaj-ntb: pikaur -Q librealsense
librealsense v2.18.1-1

otaj@otaj-ntb: pikaur -Syu
:: Synchronizing package databases...
 core is up to date
 extra is up to date
 community                                      4.9 MiB  55.8M/s 00:00 [----------------------------------------] 100%
 multilib is up to date
 sublime-text is up to date

:: Starting full AUR upgrade...
Reading repository package databases...
Reading local package database...
Reading AUR packages info...
:: warning: Following packages cannot be found in AUR:
    gnome-shell-extension-system-monitor2-git    
    python-pyrealsense2    
    technika-fonts    
Resolving AUR dependencies...

:: AUR package will be installed:
 librealsense                          v2.18.1-1            -> v2.19.1-1

:: Proceed with installation? [Y/n] 
:: [v]iew package details   [m]anually select packages
>> 

[actionless]

how pacman -Syu would work if your local package have some Group set, while newer package from the repo doesn't have that group?