OSX Lion, Xcode 4.2, GCC 4.2
I get the following error installing bson_ext 1.4.1
Building native extensions. This could take a while...
ERROR: Error installing bson_ext:
ERROR: Failed to build gem native extension.
/Users/user/.rvm/rubies/ruby-1.9.2-p290/bin/ruby extconf.rb
checking for asprintf()... *** extconf.rb failed ***
Could not create Makefile due to some reason, probably lack of
necessary libraries and/or headers. Check the mkmf.log file for more
details. You may need configuration options.