(reacting partially to your GitHub issue, also)
Running pamac-manager via terminal almost always produces warning content (for me);
for example:
Adwaita-WARNING **: 11:44:44.314: Using GtkSettings:gtk-application-prefer-dark-theme with libadwaita is unsupported. Please use AdwStyleManager:color-scheme instead.
Gdk-WARNING **: 11:44:45.611: ../gtk/gdk/wayland/gdkcursor-wayland.c:210 cursor image size (32) not an integer multiple of theme size (24)
But then, I’m using KDE Plasma on Wayland, and these types of warnings might often be expected.
However, I do find that using pamac itself is generally (but not always) trouble free; I’ve not experienced any segfault resulting from pamac. Using the Stable branch, I experience no significant issues interacting with the AUR, despite the Unstable branch being recommended for AUR users.
Your issue may be be specific to Gnome and whichever Branch you are using, or might be something else entirely. All I can state with any certainty is that what you’re experiencing doesn’t seem to be widespread; and because of that, difficult to reproduce.
As you are no doubt aware, if a condition cannot be reproduced it cannot be confirmed as a bug. My initial suggestion remains that GitHub is likely the best forum for your issue; despite any impatience with them.
Aside:- If you must use a GUI package manager, octopi is also a worthwhile consideration; and it also supports the AUR:
sudo pacman -S octopi
- Octopi (Manjaro Wiki)
Regards.
Update:- (sometime later)
I noticed another topic Bug? “Segmentation fault” and core dumps for multiple applications that bears some similarity to your issue, though it isn’t limited to Pamac.
This referred back to a likely related issue mentioned in Testing Update 2025-01-27. This is the response given by @philm:
The timeframe seems at least consistent, depending on when the respective issues were actually noticed. So, as Phil suggests, it might be worth trying:
sudo pacman -Syyuu
Regards.