Checking if your kit is complete...
Looks good
Writing Makefile for IP::Unique
cp lib/IP/Unique.pm blib/lib/IP/Unique.pm
/home/cpanrun/build/5.6.1/bin/perl -I/home/cpanrun/build/5.6.1/lib/5.6.1/i686-linux-thread-multi -I/home/cpanrun/build/5.6.1/lib/5.6.1 /home/cpanrun/build/5.6.1/lib/5.6.1/ExtUtils/xsubpp  -C++ -typemap /home/cpanrun/build/5.6.1/lib/5.6.1/ExtUtils/typemap -typemap typemap Unique.xs > Unique.xsc && mv Unique.xsc Unique.c
Please specify prototyping behavior for Unique.xs (see perlxs manual)
g++ -c -I. -Wall -O2   -DVERSION=\"0.03\" -DXS_VERSION=\"0.03\" -fpic -I/home/cpanrun/build/5.6.1/lib/5.6.1/i686-linux-thread-multi/CORE  Unique.c
In file included from /usr/lib/gcc-lib/i386-linux/2.95.2/../../../../include/g++-3/stl_alloc.h:56,
                 from /usr/lib/gcc-lib/i386-linux/2.95.2/../../../../include/g++-3/alloc.h:21,
                 from /usr/lib/gcc-lib/i386-linux/2.95.2/../../../../include/g++-3/std/bastring.h:39,
                 from /usr/lib/gcc-lib/i386-linux/2.95.2/../../../../include/g++-3/string:6,
                 from ipuniq.h:1,
                 from Unique.xs:19:
/usr/include/assert.h:79: warning: `assert' redefined
/home/cpanrun/build/5.6.1/lib/5.6.1/i686-linux-thread-multi/CORE/perl.h:2191: warning: this is the location of the previous definition
In file included from /usr/lib/gcc-lib/i386-linux/2.95.2/../../../../include/g++-3/iostream.h:31,
                 from /usr/lib/gcc-lib/i386-linux/2.95.2/../../../../include/g++-3/iterator:36,
                 from /usr/lib/gcc-lib/i386-linux/2.95.2/../../../../include/g++-3/std/bastring.h:44,
                 from /usr/lib/gcc-lib/i386-linux/2.95.2/../../../../include/g++-3/string:6,
                 from ipuniq.h:1,
                 from Unique.xs:19:
/usr/lib/gcc-lib/i386-linux/2.95.2/../../../../include/g++-3/streambuf.h:405: parse error before `const'
In file included from /usr/lib/gcc-lib/i386-linux/2.95.2/../../../../include/g++-3/iterator:36,
                 from /usr/lib/gcc-lib/i386-linux/2.95.2/../../../../include/g++-3/std/bastring.h:44,
                 from /usr/lib/gcc-lib/i386-linux/2.95.2/../../../../include/g++-3/string:6,
                 from ipuniq.h:1,
                 from Unique.xs:19:
/usr/lib/gcc-lib/i386-linux/2.95.2/../../../../include/g++-3/iostream.h:75: parse error before `char'
ppport.h:548: warning: `char * my_sv_2pvbyte(PerlInterpreter *, SV *, STRLEN *)' defined but not used
ppport.h:632: warning: `UV _grok_hex(char *, STRLEN *, I32 *, NV *)' defined but not used
ppport.h:647: warning: `UV _grok_oct(char *, STRLEN *, I32 *, NV *)' defined but not used
ppport.h:662: warning: `UV _grok_bin(char *, STRLEN *, I32 *, NV *)' defined but not used
make: *** [Unique.o] Error 1