All files in the /lib directory have been moved to /usr/lib and now /lib is a symlink to usr/lib.
During this update, pacman will identify a conflict in the /lib directory with the message:
error: failed to commit transaction (conflicting files) glibc: /lib exists in filesystem Errors occurred, no packages were upgraded.
Firstly... DO NOT USE --force!
In the simplest case, this is worked around by doing:
pacman -Syu --ignore glibc pacman -Su
There are two possible issues that might occur during this update.
Issue #1 1) Running "pacman -Syu --ignore glibc" gives:
warning: ignoring package glibc-2.16.0-2 warning: cannot resolve "glibc>=2.16", a dependency of "gcc-libs" ...
:: The following packages cannot be upgraded due to unresolvable dependencies: binutils gcc gcc-libs
Do you want to skip the above packages for this upgrade [y/N]
Say "y" to skipping the packages, then install them using:
pacman -Sd binutils gcc gcc-libs
Note the use of a single "-d" only ignores the versioning of dependencies and not the actual dependency itself. Then finish the update using:
Issue #2) The final "pacman -Su" still has conflicts in /lib