it won't overwrite the /usr/lib64 folder.
post the exact errors you're getting
The output of `pacman -S base' command is: (50/50) checking keys in keyring (50/50) checking package integrity (50/50) loading package files (50/50) checking for file conflicts (50/50) checking available disk space ( 1/50) reinstalling filesystem error: extract: not overwriting dir with file /usr/lib64 error: problem occured while upgrading filesystem error: could not commit transaction error: failed to commit transaction (rransaction aborted) Errors occured, no packages were upgraded.
I know that that the /usr/lib64 is a symlink only.
error: extract: not overwriting dir with file /usr/lib64 which means /usr/lib64 is a directory on your system?? since when didn't you upgrade? try "pacman -Syu -ignore filesystem ; pacman -S filesystem" otherwise read through all of the https://www.archlinux.org/news/ and check the steps you need to do for every update you missed so far. -- damjan