Most people when they get into developing for Ruby on Rails on OS X probably use this handy guide to install the latest Ruby and Rails on OS X

If you build Ruby on your Leopard installation to use the latest and greatest ruby-1.8.6-p111 release following that guide you’ll probably be greeted with something like this upon calling make:

gcc -I/sw/include  -fno-common -pipe -fno-common  -DRUBY_EXPORT  -I. -I. -I/sw/include -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  dmyext.o
gcc -I/sw/include  -fno-common -pipe -fno-common  -DRUBY_EXPORT  -I. -I. -I/sw/include -c main.c
gcc -I/sw/include  -fno-common -pipe -fno-common  -DRUBY_EXPORT  -I. -I. -I/sw/include -c dmydln.c
gcc -I/sw/include  -fno-common -pipe -fno-common  -DRUBY_EXPORT  -L. -L/sw/lib   main.o dmydln.o libruby-static.a -lpthread -ldl -lobjc   -o miniruby
ruby: [BUG] Segmentation fault
ruby 1.8.6 (2007-09-24) [i686-darwin9.1.0]

make: *** [.rbconfig.time] Abort trap

It’s a simple fix. Just remove the --enable-pthread configuration option.

	./configure --prefix=/usr/local --disable-pthread --with-readline-dir=/usr/local --enable-shared

And your make call should run without incident. The only real change I’ve noticed (no doubt related to disabling pthreads) is that my Ruby benchmark takes longer to run…

	Ruby 1.8.6 patch 111 on i686-darwin9.1.0
	It took 10.488273 seconds to run. 95344 iterations per second.