Installing libv8 3.16.14.11 (was 3.16.14.3) with native extensions Gem::Ext::BuildError: ERROR: Failed to build gem native extension. /Users/user/.rbenv/versions/2.1.3/bin/ruby extconf.rb creating Makefile Compiling v8 for x64 Using python 2.7.6 Using compiler: /usr/bin/c++ (clang version 6.1.0) /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/libtool: file: /