Установка Wit gem вызывает неясную ошибку Ruby

Question

Я создал совершенно новое приложение Rails и добавил gem wit в Gemfile. Теперь, когда я запускаю bundle install, я получаю эту ошибку. В Googling, чтобы найти решение, я столкнулся с четырьмя различными возможностями, но ни один из них не применим к моей среде dev (OSX 10.9.5, Brew 0.9.5). Кто-нибудь решил эту проблему?

Ссылки:

The compiler failed to generate an executable file. (RuntimeError)

https://github.com/CocoaPods/CocoaPods/issues/1727

https://github.com/copiousfreetime/hitimes/issues/26

https://teamtreehouse.com/forum/rails-gem-wont-install-properly

... 
Using turbolinks 2.5.2 
Using uglifier 2.5.3 

Gem::Ext::BuildError: ERROR: Failed to build gem native extension. 

    /Users/user/.rvm/rubies/ruby-2.1-head/bin/ruby -r ./siteconf20141204-96223-d2ceuv.rb extconf.rb 
    % Total % Received % Xferd Average Speed Time Time  Time Current 
           Dload Upload Total Spent Left Speed 
100 12.7M 100 12.7M 0  0 741k  0 0:00:17 0:00:17 --:--:-- 723k 
checking for main() in -lsox... *** 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 
    --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/user/.rvm/rubies/ruby-2.1-head/bin/ruby 
    --with-wit-dir 
    --without-wit-dir 
    --with-wit-include 
    --without-wit-include=${wit-dir}/include 
    --with-wit-lib 
    --without-wit-lib=${wit-dir}/lib 
    --with-soxlib 
    --without-soxlib 
/Users/user/.rvm/rubies/ruby-2.1-head/lib/ruby/2.1.0/mkmf.rb:456:in `try_do': The compiler failed to generate an executable file. (RuntimeError) 
You have to install development tools first. 
    from /Users/user/.rvm/rubies/ruby-2.1-head/lib/ruby/2.1.0/mkmf.rb:541:in `try_link0' 
    from /Users/user/.rvm/rubies/ruby-2.1-head/lib/ruby/2.1.0/mkmf.rb:556:in `try_link' 
    from /Users/user/.rvm/rubies/ruby-2.1-head/lib/ruby/2.1.0/mkmf.rb:742:in `try_func' 
    from /Users/user/.rvm/rubies/ruby-2.1-head/lib/ruby/2.1.0/mkmf.rb:973:in `block in have_library' 
    from /Users/user/.rvm/rubies/ruby-2.1-head/lib/ruby/2.1.0/mkmf.rb:918:in `block in checking_for' 
    from /Users/user/.rvm/rubies/ruby-2.1-head/lib/ruby/2.1.0/mkmf.rb:351:in `block (2 levels) in postpone' 
    from /Users/user/.rvm/rubies/ruby-2.1-head/lib/ruby/2.1.0/mkmf.rb:321:in `open' 
    from /Users/user/.rvm/rubies/ruby-2.1-head/lib/ruby/2.1.0/mkmf.rb:351:in `block in postpone' 
    from /Users/user/.rvm/rubies/ruby-2.1-head/lib/ruby/2.1.0/mkmf.rb:321:in `open' 
    from /Users/user/.rvm/rubies/ruby-2.1-head/lib/ruby/2.1.0/mkmf.rb:347:in `postpone' 
    from /Users/user/.rvm/rubies/ruby-2.1-head/lib/ruby/2.1.0/mkmf.rb:917:in `checking_for' 
    from /Users/user/.rvm/rubies/ruby-2.1-head/lib/ruby/2.1.0/mkmf.rb:968:in `have_library' 
    from extconf.rb:33:in `<main>' 

extconf failed, exit code 1 

Gem files will remain installed in /Users/user/.rvm/gems/ruby-2.1-head/gems/wit-1.0.5 for inspection. 
Results logged to /Users/user/.rvm/gems/ruby-2.1-head/extensions/x86_64-darwin-13/2.1.0/wit-1.0.5/gem_make.out 
An error occurred while installing wit (1.0.5), and Bundler cannot continue. 
Make sure that `gem install wit -v '1.0.5'` succeeds before bundling. 

Вот выход для mkmf.log

$ cat /Users/user/.rvm/gems/ruby-2.1-head/extensions/x86_64-darwin-13/2.1.0/wit-1.0.5/mkmf.log 
"/usr/bin/clang -o conftest -I/Users/user/.rvm/rubies/ruby-2.1-head/include/ruby-2.1.0/x86_64-darwin13.0 -I/Users/user/.rvm/rubies/ruby-2.1-head/include/ruby-2.1.0/ruby/backward -I/Users/user/.rvm/rubies/ruby-2.1-head/include/ruby-2.1.0 -I. -I/Users/user/.rvm/gems/ruby-2.1-head/gems/wit-1.0.5/ext/wit/libwit/include -I/Users/user/.rvm/rubies/ruby-2.1-head/include -I/usr/local/opt/libyaml/include -I/usr/local/opt/readline/include -I/usr/local/opt/libksba/include -I/usr/local/opt/openssl/include -D_XOPEN_SOURCE -D_DARWIN_C_SOURCE -D_DARWIN_UNLIMITED_SELECT -D_REENTRANT -O3 -fno-fast-math -ggdb3 -Wall -Wextra -Wno-unused-parameter -Wno-parentheses -Wno-long-long -Wno-missing-field-initializers -Wunused-variable -Wpointer-arith -Wwrite-strings -Wdeclaration-after-statement -Wshorten-64-to-32 -Wimplicit-function-declaration -Wdivision-by-zero -Wextra-tokens -fno-common -pipe conftest.c -L. -L/Users/user/.rvm/rubies/ruby-2.1-head/lib -L/Users/user/.rvm/gems/ruby-2.1-head/gems/wit-1.0.5/ext/wit/libwit/lib -L/Users/user/.rvm/rubies/ruby-2.1-head/lib -L/usr/local/opt/libyaml/lib -L/usr/local/opt/readline/lib -L/usr/local/opt/libksba/lib -L/usr/local/opt/openssl/lib -L. -fstack-protector -L/usr/local/lib -L/usr/local/opt/libyaml/lib -L/usr/local/opt/readline/lib -L/usr/local/opt/libksba/lib -L/usr/local/opt/openssl/lib -lwit -lsox -lcurl -lruby.2.1.0 -lpthread -lgmp -ldl -lobjc " 
ld: library not found for -lsox 
clang: error: linker command failed with exit code 1 (use -v to see invocation) 
checked program was: 
/* begin */ 
1: #include "ruby.h" 
2: 
3: int main(int argc, char **argv) 
4: { 
5: return 0; 
6: } 
/* end */ 

Answer 1

Я получил эту проблему решить путем переустановки инструментов X-Code в командной строке: xcode-install --select