Same problem with 1.8.4:

gcc -g -O2  -DRUBY_EXPORT  -I. -I.  -c ruby.c
gcc -g -O2  -DRUBY_EXPORT  -I. -I.  -c signal.c
gcc -g -O2  -DRUBY_EXPORT  -I. -I.  -c sprintf.c
gcc -g -O2  -DRUBY_EXPORT  -I. -I.  -c st.c
gcc -g -O2  -DRUBY_EXPORT  -I. -I.  -c string.c
string.c: In function 'rb_str_index_m':
string.c:1133: warning: pointer targets in initialization differ in
signedness
string.c: In function 'rb_str_rindex_m':
string.c:1255: warning: pointer targets in initialization differ in
signedness
string.c:1256: warning: pointer targets in initialization differ in
signedness
gcc -g -O2  -DRUBY_EXPORT  -I. -I.  -c struct.c
gcc -g -O2  -DRUBY_EXPORT  -I. -I.  -c time.c
gcc -g -O2  -DRUBY_EXPORT  -I. -I.  -c util.c
gcc -g -O2  -DRUBY_EXPORT  -I. -I.  -c variable.c
gcc -g -O2  -DRUBY_EXPORT  -I. -I.  -c version.c
gcc -g -O2  -DRUBY_EXPORT  -I. -I.  -c ./missing/flock.c
gcc -g -O2  -DRUBY_EXPORT  -I. -I.  -c dmyext.c
ar rcu libruby-static.a array.o bignum.o class.o compar.o dir.o dln.o
enum.o error.o eval.o file.o gc.o hash.o inits.o io.o marshal.o math.o
numeric.o object.o pack.o parse.o process.o prec.o random.o range.o
re.o regex.o ruby.o signal.o sprintf.o st.o string.o struct.o time.o
util.o variable.o version.o flock.o  dmyext.o
gcc -g -O2  -DRUBY_EXPORT  -I. -I.  -c main.c
gcc main.o  libruby-static.a -ldl -lcrypt -lm   -o miniruby -g -O2
-DRUBY_EXPORT
make: *** [.rbconfig.time] Segmentation fault (core dumped)

Here's the gcc info

Using built-in specs.
Target: powerpc-ibm-aix5.3.0.0
Configured with: ../gcc-4.0.0/configure --disable-nls
Thread model: aix
gcc version 4.0.0


I am very willing to help debug this problem. I will work on it myself
but i don't want to duplicate anyone's effort or work on what is really
an operator (i.e. me) problem.

Thanks,

Ron