libfdt.a git compilation fail

I don't know the commit tags but I checked out dtc on the 28 of october at 20:27 in the tree of qemu (also git checkout out tonight). The compilation fail at line 234 in qemu/dtc/Makefile so I inserted that line:

@$ /usr/bin/strace -o /usr/src/qemu_build/error.log.txt /usr/bin/ar $@

into the makefile at position 234 to see what is the exact problem but the strace log is inconclusive.

for the error: /usr/bin/ar: deux operations différentes spécifiées

liberal translation is: two different operation specified.

the distribution is arch linux with binutils 2.23.2, gcc 4.8.2 and kernel kvm-3.12.0-rc5 from git.