Failed to build gem native extension.

First off thanks for building this gem! This is the output from gem install rsox.

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

    /Users/***/.rbenv/versions/2.0.0-p0/bin/ruby extconf.rb
extconf.rb:3:in `<main>': Use RbConfig instead of obsolete and deprecated Config.
extconf.rb:3:in `<main>': Use RbConfig instead of obsolete and deprecated Config.
extconf.rb:4:in `<main>': Use RbConfig instead of obsolete and deprecated Config.
checking for sox_format_init() in -lsox... yes
checking for sox.h... yes
creating Makefile

make
compiling rsox.c
rsox.c:254: error: expected ‘;’, ‘,’ or ‘)’ before ‘UNUSED’
rsox.c: In function ‘rsox_rubyblock_handler’:
rsox.c:270: error: ‘rsox_rubyblock_flow’ undeclared (first use in this function)
rsox.c:270: error: (Each undeclared identifier is reported only once
rsox.c:270: error: for each function it appears in.)
make: *** [rsox.o] Error 1

ruby --version ruby 2.0.0p0 (2013-02-24 revision 39474) [x86_64-darwin12.2.1]

gcc --version i686-apple-darwin11-llvm-gcc-4.2 (GCC) 4.2.1 (Based on Apple Inc. build 5658) (LLVM build 2336.11.00)

I tried brew install sox and then gem install rsox still getting the below issue on Yosemite:

gem install rsox

Fetching: rsox-0.0.2.gem (100%) Building native extensions. This could take a while... /Users/sri/.rvm/rubies/ruby-2.1.2/lib/ruby/site_ruby/2.1.0/rubygems/ext/builder.rb:73: warning: Insecure world writable dir /usr/local/bin in PATH, mode 040757 ERROR: Error installing rsox: ERROR: Failed to build gem native extension.

/Users/sri/.rvm/rubies/ruby-2.1.2/bin/ruby -r ./siteconf20150109-85688-1mttcl2.rb extconf.rb

extconf.rb:3:in <main>': Use RbConfig instead of obsolete and deprecated Config. extconf.rb:3:in

': Use RbConfig instead of obsolete and deprecated Config. extconf.rb:4:in `

': Use RbConfig instead of obsolete and deprecated Config. checking for sox_format_init() in -lsox... no * 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.

Provided configuration options: --with-opt-dir --without-opt-dir --with-opt-include --without-opt-include=${opt-dir}/include --with-opt-lib --without-opt-lib=${opt-dir}/lib --with-make-prog --without-make-prog --srcdir=. --curdir --ruby=/Users/sri/.rvm/rubies/ruby-2.1.2/bin/ruby --with-rsox-dir --without-rsox-dir --with-rsox-include --without-rsox-include=${rsox-dir}/include --with-rsox-lib --without-rsox-lib=${rsox-dir}/lib --with-soxlib --without-soxlib

extconf failed, exit code 1

Gem files will remain installed in /Users/sri/.rvm/gems/ruby-2.1.2/gems/rsox-0.0.2 for inspection. Results logged to /Users/sri/.rvm/gems/ruby-2.1.2/extensions/x86_64-darwin-13/2.1.0-static/rsox-0.0.2/gem_make.out

faridco / rsox

Failed to build gem native extension. #6