glibc update problem , archlinux

conflict error that i've found during system update:

error: failed to commit transaction (conflicting files)
glibc: /lib exists in filesystem
Errors occurred, no packages were upgraded.

try to do this:

pacman -Syu --ignore glibc
pacman -Su 

if you find the same error after you have entered pacman -Su :

1) remove /lib/modules

mkdir backup
sudo mv /lib/modules /home/user/backup

or simply sudo rm -rf /lib/modules to erase this folder.

sudo pacman -Su

Have you found the same error? go to point 2!

2) read this useful guide in english. It helps to solve this problem:

https://bbs.archlinux.org/viewtopic.php?pid=1129800#p1129800

(post #39)

ufficial arch linux guide:

https://wiki.archlinux.org/index.php/DeveloperWiki:usrlib