r2220でコンパイルに失敗

cd ext/digest/rmd160
../../../miniruby -I../../.. -I../../../lib -r rbconfig -e "RbConfig::CONFIG['libdir'] = '../../..'; require './extconf.rb'"
checking for main() in -lcrypto... The complier failed to generate an executable file.  
You have to install development tools first.
 (RuntimeError)
rake aborted!
Command failed with status (1): [../../../miniruby -I../../.. -I../../../li...]

(See full trace by running task with --trace)

原因はなんだろ。あとで見てみよう。