[arch-general] pacman error: target not found

[Mathias Huber]

Dear Archers,

I've been a happy Arch Linux user for years, but now I'm having trouble 
updating. Can anyone help?

[root at archlinux huber]# pacman -Syu
:: Synchronizing package databases...
[...]
:: Starting full system upgrade...
:: Replace libwebkit with extra/webkitgtk2? [Y/n]
[...]
resolving dependencies...
looking for inter-conflicts...
warning: removing 'libgl' from target list because it conflicts with 
'nvidia-utils'
error: failed to prepare transaction (could not satisfy dependencies)
:: nouveau-dri: requires libgl=9.0
[root at archlinux huber]# pacman -R nouveau-dri
error: target not found: nouveau-dri

How do I resolve this?

Best,
Mathias