マシンで kdtree gem のネイティブ拡張機能をコンパイルする際に問題が発生する場合があります。エラーは次のようになります。
X-MacBook-Pro:Pitot X$ sudo gem install kdtree
Building native extensions. This could take a while...
ERROR: Error installing kdtree:
ERROR: Failed to build gem native extension.
/Users/X/.rvm/rubies/ruby-1.9.3-p327/bin/ruby extconf.rb
creating Makefile
make
compiling kdtree.c
In file included from /Users/X/.rvm/rubies/ruby-1.9.3-p327/include/ruby-1.9.1/ruby.h:32,
from kdtree.c:1:
/Users/X/.rvm/rubies/ruby-1.9.3-p327/include/ruby-1.9.1/ruby/ruby.h:48:21: error: string.h: No such file or directory
/Users/X/.rvm/rubies/ruby-1.9.3-p327/include/ruby-1.9.1/ruby/ruby.h:58:21: error: stdint.h: No such file or directory
/Users/X/.rvm/rubies/ruby-1.9.3-p327/include/ruby-1.9.1/ruby/ruby.h:61:23: error: inttypes.h: No such file or directory
/Users/X/.rvm/rubies/ruby-1.9.3-p327/include/ruby-1.9.1/ruby/ruby.h:65:19: error: stdio.h: No such file or directory
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