问在OSX Mountain Lion (localmemcache)上安装Google-api-client Ruby失败

EN

Building native extensions.  This could take a while...
ERROR:  Error installing localmemcache:
    ERROR: Failed to build gem native extension.

        sh ./configure --prefix=/Users/rental/.rvm/gems/ruby-1.9.3-p125/gems/localmemcache-0.4.4/src/ruby-binding
checking for gcc... gcc
checking for C compiler default output file name... a.out
checking whether the C compiler works... yes
checking whether we are cross compiling... no
checking for suffix of executables... 
checking for suffix of object files... o
checking whether we are using the GNU C compiler... yes
checking whether gcc accepts -g... yes
checking for gcc option to accept ISO C89... none needed
checking for ranlib... ranlib
checking for apple OS X... 
->  Apple OS X is not supported because it doesn't have 
    sem_getvalue and sem_timedwait!
    You may set the environment variable LMC_FORCE_BUILD 
    to build a version of localmemcache that cannot recover 
    from crashes.

sudo gem install google-api-client --development --force --no-rdoc --no-ri