classpath/tools/tools.zip:0:0: fatal error: not a valid Java .class file

[YuGiOhJCJ Mailing-List]

Hello,

I try to build gcc 5.3.0 on Slackware 14.1 but I got this error:
$ ../configure --prefix=/usr --enable-languages=c,c++,java
$ make
[...]
make[3]: Entering directory `/tmp/build/openjdk/gcc-5.3.0/build/i686-pc-linux-gnu/libjava'
/bin/sh ./libtool  --tag=GCJ   --mode=compile /tmp/build/openjdk/gcc-5.3.0/build/./gcc/gcj -B/tmp/build/openjdk/gcc-5.3.0/build/i686-pc-linux-gnu/libjava/ -B/tmp/build/openjdk/gcc-5.3.0/build/./gcc/ -B/usr/i686-pc-linux-gnu/bin/ -B/usr/i686-pc-linux-gnu/lib/ -isystem /usr/i686-pc-linux-gnu/include -isystem /usr/i686-pc-linux-gnu/sys-include    -ffloat-store -fomit-frame-pointer -Usun -fclasspath= -fbootclasspath=../../../libjava/classpath/lib --encoding=UTF-8 -Wno-deprecated -fbootstrap-classes -findirect-dispatch -fno-bootstrap-classes -fno-indirect-classes -fsource-filename=/tmp/build/openjdk/gcc-5.3.0/build/i686-pc-linux-gnu/libjava/classpath/tools/all-classes.lst -g -O2 -MT classpath/tools/libgcj_tools_la-tools.lo -MD -MP -MF classpath/tools/.deps/libgcj_tools_la-tools.Tpo -c -o classpath/tools/libgcj_tools_la-tools.lo `test -f 'classpath/tools/tools.zip' || echo '../../../libjava/'`classpath/tools/tools.zip
libtool: compile:  /tmp/build/openjdk/gcc-5.3.0/build/./gcc/gcj -B/tmp/build/openjdk/gcc-5.3.0/build/i686-pc-linux-gnu/libjava/ -B/tmp/build/openjdk/gcc-5.3.0/build/./gcc/ -B/usr/i686-pc-linux-gnu/bin/ -B/usr/i686-pc-linux-gnu/lib/ -isystem /usr/i686-pc-linux-gnu/include -isystem /usr/i686-pc-linux-gnu/sys-include -ffloat-store -fomit-frame-pointer -Usun -fclasspath= -fbootclasspath=../../../libjava/classpath/lib --encoding=UTF-8 -Wno-deprecated -fbootstrap-classes -findirect-dispatch -fno-bootstrap-classes -fno-indirect-classes -fsource-filename=/tmp/build/openjdk/gcc-5.3.0/build/i686-pc-linux-gnu/libjava/classpath/tools/all-classes.lst -g -O2 -MT classpath/tools/libgcj_tools_la-tools.lo -MD -MP -MF classpath/tools/.deps/libgcj_tools_la-tools.Tpo -c classpath/tools/tools.zip  -fPIC -o classpath/tools/.libs/libgcj_tools_la-tools.o
In file included from <built-in>:0:0:
classpath/tools/tools.zip:0:0: fatal error: not a valid Java .class file
compilation terminated.
make[3]: *** [classpath/tools/libgcj_tools_la-tools.lo] Error 1
make[3]: Leaving directory `/tmp/build/openjdk/gcc-5.3.0/build/i686-pc-linux-gnu/libjava'
make[2]: *** [all-recursive] Error 1
make[2]: Leaving directory `/tmp/build/openjdk/gcc-5.3.0/build/i686-pc-linux-gnu/libjava'
make[1]: *** [all-target-libjava] Error 2
make[1]: Leaving directory `/tmp/build/openjdk/gcc-5.3.0/build'
make: *** [all] Error 2

Do you know why?

Thank you.
Best regards.