pacman update fails: gcc requires gcc-libs=4.7.0-3

I ran pacman -Syu this morning and there's an update to pacman to install first, so I say yes but it fails like this:

:: Synchronising package databases...
 core is up to date
 extra is up to date
 community is up to date
:: The following packages should be upgraded first :
    pacman
:: Do you want to cancel the current operation
:: and upgrade these packages now? [Y/n] y

resolving dependencies...
looking for inter-conflicts...
error: failed to prepare transaction (could not satisfy dependencies)
:: gcc: requires gcc-libs=4.7.0-3

But I have gcc-libs 4.7.0-3 installed:

pacman -Qs gcc-libs
 
local/gcc-libs 4.7.0-3 (base)
    Runtime libraries shipped by GCC

I solved it by updated pacman on its own e.g. pacman -S pacman