avr/bin/ld: skipping incompatible /usr/lib/gcc/avr/4.9.0/libgcc.a when searching for -lgcc

I want try to use gcc 4.9.
Starting from a working toolchain of Fedora 19 with avr-gcc 4.8; I get
the last snapshot and buid it inside rpm build system with:
../gcc-4.9/configure --prefix=/usr --mandir=/usr/share/man
--infodir=/usr/share/info --target=avr --enable-languages=c,c++ -
-disable-nls --disable-libssp --with-system-zlib
--enable-version-specific-runtime-libs --with-pkgversion=Fedora
4.9-1.fc19 --with-bugurl=https://bugzilla.redhat.com/

I install the rpm and compile works well but at link stage:

/usr/bin/avr-gcc -mmcu=atmega328p -Wl,--gc-sections -Wl,-Map -Wl,t.map -o .build/uno/firmware.elf .build/uno/src/helloworld_rx.o -v
Using built-in specs.
COLLECT_GCC=/usr/bin/avr-gcc
COLLECT_LTO_WRAPPER=/usr/libexec/gcc/avr/4.9.0/lto-wrapper
Target: avr
Configured with: ../gcc-4.9/configure --prefix=/usr --mandir=/usr/share/man --infodir=/usr/share/info --target=avr --enable-languages=c,c++ --disable-nls --disable-libssp --with-system-zlib --enable-version-specific-runtime-libs --with-pkgversion='Fedora 4.9-1.fc19' --with-bugurl=https://bugzilla.redhat.com/
Thread model: single
gcc version 4.9.0 20140316 (experimental) (Fedora 4.9-1.fc19) 
COMPILER_PATH=/usr/libexec/gcc/avr/4.9.0/:/usr/libexec/gcc/avr/4.9.0/:/usr/libexec/gcc/avr/:/usr/lib/gcc/avr/4.9.0/:/usr/lib/gcc/avr/:/usr/lib/gcc/avr/4.9.0/../../../../avr/bin/
LIBRARY_PATH=/usr/lib/gcc/avr/4.9.0/avr5/:/usr/lib/gcc/avr/4.9.0/../../../../avr/lib/avr5/:/usr/lib/gcc/avr/4.9.0/:/usr/lib/gcc/avr/4.9.0/../../../../avr/lib/
COLLECT_GCC_OPTIONS='-mmcu=atmega328p' '-o' '.build/uno/firmware.elf' '-v'
 /usr/libexec/gcc/avr/4.9.0/collect2 -plugin /usr/libexec/gcc/avr/4.9.0/liblto_plugin.so -plugin-opt=/usr/libexec/gcc/avr/4.9.0/lto-wrapper -plugin-opt=-fresolution=/tmp/ccaF7CSb.res -plugin-opt=-pass-through=-lgcc -plugin-opt=-pass-through=-lm -plugin-opt=-pass-through=-lc -m avr5 -Tdata 0x800100 -o .build/uno/firmware.elf /usr/lib/gcc/avr/4.9.0/../../../../avr/lib/avr5/crtm328p.o -L/usr/lib/gcc/avr/4.9.0/avr5 -L/usr/lib/gcc/avr/4.9.0/../../../../avr/lib/avr5 -L/usr/lib/gcc/avr/4.9.0 -L/usr/lib/gcc/avr/4.9.0/../../../../avr/lib --gc-sections -Map t.map .build/uno/src/helloworld_rx.o --start-group -lgcc -lm -lc --end-group
/usr/lib/gcc/avr/4.9.0/../../../../avr/bin/ld: skipping incompatible /usr/lib/gcc/avr/4.9.0/avr5/libgcc.a when searching for -lgcc
/usr/lib/gcc/avr/4.9.0/../../../../avr/bin/ld: skipping incompatible /usr/lib/gcc/avr/4.9.0/libgcc.a when searching for -lgcc
/usr/lib/gcc/avr/4.9.0/../../../../avr/bin/ld: cannot find -lgcc
collect2: error: ld returned 1 exit status


objdump results:

avr-objdump -f .build/uno/src/helloworld_rx.o

.build/uno/src/helloworld_rx.o:     file format elf32-avr
architecture: avr:5, flags 0x00000011:
HAS_RELOC, HAS_SYMS
start address 0x00000000



avr-objdump -f /usr/lib/gcc/avr/4.9.0/avr5/libgcc.a|head -n 20
In archive /usr/lib/gcc/avr/4.9.0/avr5/libgcc.a:

_absvhi2.o:     file format elf32-little
architecture: UNKNOWN!, flags 0x00000011:
HAS_RELOC, HAS_SYMS
start address 0x00000000


_addvhi3.o:     file format elf32-avr
architecture: avr:5, flags 0x00000011:
HAS_RELOC, HAS_SYMS
start address 0x00000000


_subvhi3.o:     file format elf32-avr
architecture: avr:5, flags 0x00000011:
HAS_RELOC, HAS_SYMS
start address 0x00000000

Trying to recompile binutils and libc do not help.
Any suggestions?

avr-gcc --version
avr-gcc (Fedora 4.9-1.fc19) 4.9.0 20140316 (experimental)
Copyright (C) 2014 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

rpm -q avr-binutils
avr-binutils-2.23.1-2.fc19.x86_64

rpm -q avr-libc
avr-libc-1.8.0-5.fc19.noarch


Paolo