make error when installing `ruby-1.8.7-p334` with `rvm` on Snow Leopard

Some of my Ruby gems stopped working after installing Snow Leopard (OS X 10.6). I also installed Xcode (to get make) and get the following error when installing ruby开发者_如何转开发-1.8.7-p334 with rvm. I was able to succesfully install it when running Leopard. Any help would be appreciated.

Macintosh:haloror patelc75$ rvm install ruby-1.8.7-p334

Installing Ruby from source to: /Users/patelc75/.rvm/rubies/ruby-1.8.7-p334, this may take a while depending on your cpu(s)...
ruby-1.8.7-p334 - #fetching
ruby-1.8.7-p334 - #extracted to /Users/patelc75/.rvm/src/ruby-1.8.7-p334 (already extracted)
ruby-1.8.7-p334 - #configuring
ruby-1.8.7-p334 - #compiling
ERROR: Error running 'make ', please read /Users/patelc75/.rvm/log/ruby-1.8.7-p334/make.log
ERROR: There has been an error while running make. Halting the installation.

Macintosh:haloror patelc75$ more /Users/patelc75/.rvm/log/ruby-1.8.7-p334/make.log

[2011-08-23 17:21:55] make
gcc -g -O2  -fno-common -pipe -fno-common    -DRUBY_EXPORT  -L.    main.o dmydln.o libruby-static.a -ldl -lobjc   -o miniruby
Undefined symbols:
"_Init_ext", referenced from:
  _require_libraries in libruby-static.a(ruby.o)
ld: symbol(s) not found
collect2: ld returned 1 exit status
make: *** [miniruby] Error 1

Please check the log file at /Users/patelc75/.rvm/log/ruby-1.8.7-p334/make.log readline may be the issue most of the time. to fix that please do

rvm pkg install readline

before that you might want to do

rvm remove 1.8.7
rvm cleanup