Checking if your kit is complete...
Looks good
Writing Makefile for Sun::Solaris::Ucred
cp Ucred.pm blib/lib/Sun/Solaris/Ucred.pm
/export/home/cpanrun/build/5.6.1/bin/perl -I/export/home/cpanrun/build/5.6.1/lib/5.6.1/sun4-solaris-thread-multi -I/export/home/cpanrun/build/5.6.1/lib/5.6.1 /export/home/cpanrun/build/5.6.1/lib/5.6.1/ExtUtils/xsubpp  -typemap /export/home/cpanrun/build/5.6.1/lib/5.6.1/ExtUtils/typemap -typemap typemap Ucred.xs > Ucred.xsc && mv Ucred.xsc Ucred.c
gcc -c  -DUSE_REENTRANT_API -D_POSIX_PTHREAD_SEMANTICS -D_REENTRANT -fno-strict-aliasing -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 -O   -DVERSION=\"1.1\" -DXS_VERSION=\"1.1\" -fPIC -I/export/home/cpanrun/build/5.6.1/lib/5.6.1/sun4-solaris-thread-multi/CORE  Ucred.c
Ucred.xs:12: ucred.h: No such file or directory
Ucred.xs:13: priv.h: No such file or directory
make: *** [Ucred.o] Error 1