Aargh, I expected as much. Sometimes stderr / stdout (look up each term if you’d like) messages aren’t always helpful.
It sounds like you’ve already made sure you were fully up to date via pacman, so the next step would be using GDB to debug the program.
First, install the Pamac debug packages:
sudo pacman -S --needed gdb libpamac-debug pamac-cli-debug
Then one of the following:
If you’re using pamac-gtk (Gtk 4):
sudo pacman -S pamac-debug
If you’re using pamac-gtk3 (Gtk 3):
sudo pacman -S pamac-gtk3-debug
Then run:
gdb -q --args pamac-manager
Enable debuginfod for the session when prompted. It may take some time for the debug info to download.
Example:
❯ gdb -q --args pamac-manager
Reading symbols from pamac-manager...
Reading symbols from /usr/lib/debug/usr/bin/pamac-manager.debug...
(gdb) run
Starting program: /usr/bin/pamac-manager
This GDB supports auto-downloading debuginfo from the following URLs:
<https://debuginfod.archlinux.org>
Enable debuginfod for this session? (y or [n]) y
Debuginfod has been enabled.
To make this setting permanent, add 'set debuginfod enabled on' to .gdbinit.
Downloading separate debug info for ...
After that’s finished, gdb will attempt to run pamac-manager. That will be the important output.
Afterward, you can type exit at the (gdb) prompt.