title: Can't install gevent OSX 10.11
body: <p>Trying to install gevent using Homebrew on OSX 10.11 latest public beta. When running the install, it outputs the following errors (Sorry for the large wall of code, not sure exactly where the error is)</p>
  
  <pre><code>    clang -DNDEBUG -g -fwrapv -O3 -Wall -Wstrict-prototypes -I /opt/local/include -L /opt/local/lib -U__llvm__ -DLIBEV_EMBED=1 -DEV_COMMON= -DEV_CLEANUP_ENABLE=0 -DEV_EMBED_ENABLE=0 -DEV_PERIODIC_ENABLE=0 -Ibuild/temp.macosx-10.11-x86_64-2.7/libev -Ilibev -I/usr/local/include -I/usr/local/opt/openssl/include -I/usr/local/opt/sqlite/include -I/usr/local/Cellar/python/2.7.10_2/Frameworks/Python.framework/Versions/2.7/include/python2.7 -c gevent/gevent.core.c -o build/temp.macosx-10.11-x86_64-2.7/gevent/gevent.core.o
    clang: warning: argument unused during compilation: '-L/opt/local/lib'
    In file included from gevent/gevent.core.c:249:
    In file included from gevent/libev.h:2:
    libev/ev.c:483:48: warning: '/*' within block comment [-Wcomment]
    /*#define MIN_INTERVAL  0.00000095367431640625 /* 1/2**20, good till 2200 */
                                                   ^
    libev/ev.c:1029:42: error: '_Noreturn' keyword must precede function declarator
      ecb_inline void ecb_unreachable (void) ecb_noreturn;
                                             ^~~~~~~~~~~~
      _Noreturn
    libev/ev.c:832:26: note: expanded from macro 'ecb_noreturn'
      #define ecb_noreturn   _Noreturn
                             ^
    libev/ev.c:1625:31: warning: 'extern' variable has an initializer [-Wextern-initializer]
      EV_API_DECL struct ev_loop *ev_default_loop_ptr = 0; /* needs to be initialised to make it a definition despite extern */
                                  ^
    libev/ev.c:1796:7: warning: unused variable 'ocur_' [-Wunused-variable]
          array_needsize (ANPENDING, pendings [pri], pendingmax [pri], w_-&gt;pending, EMPTY2);
          ^
    libev/ev.c:1758:22: note: expanded from macro 'array_needsize'
          int ecb_unused ocur_ = (cur);                                     \
                         ^
    libev/ev.c:1807:3: warning: unused variable 'ocur_' [-Wunused-variable]
      array_needsize (W, rfeeds, rfeedmax, rfeedcnt + 1, EMPTY2);
      ^
    libev/ev.c:1758:22: note: expanded from macro 'array_needsize'
          int ecb_unused ocur_ = (cur);                                     \
                         ^
    libev/ev.c:1934:7: warning: unused variable 'ocur_' [-Wunused-variable]
          array_needsize (int, fdchanges, fdchangemax, fdchangecnt, EMPTY2);
          ^
    libev/ev.c:1758:22: note: expanded from macro 'array_needsize'
          int ecb_unused ocur_ = (cur);                                     \
                         ^
    In file included from gevent/gevent.core.c:249:
    In file included from gevent/libev.h:2:
    In file included from libev/ev.c:2484:
    libev/ev_kqueue.c:50:3: warning: unused variable 'ocur_' [-Wunused-variable]
      array_needsize (struct kevent, kqueue_changes, kqueue_changemax, kqueue_changecnt, EMPTY2);
      ^
    libev/ev.c:1758:22: note: expanded from macro 'array_needsize'
          int ecb_unused ocur_ = (cur);                                     \
                         ^
    In file included from gevent/gevent.core.c:249:
    In file included from gevent/libev.h:2:
    In file included from libev/ev.c:2490:
    libev/ev_poll.c:66:7: warning: unused variable 'ocur_' [-Wunused-variable]
          array_needsize (struct pollfd, polls, pollmax, pollcnt, EMPTY2);
          ^
    libev/ev.c:1758:22: note: expanded from macro 'array_needsize'
          int ecb_unused ocur_ = (cur);                                     \
                         ^
    libev/ev.c:3648:34: warning: '&amp;' within '|' [-Wbitwise-op-parentheses]
      fd_change (EV_A_ fd, w-&gt;events &amp; EV__IOFDSET | EV_ANFD_REIFY);
                           ~~~~~~~~~~^~~~~~~~~~~~~ ~
    libev/ev.c:3648:34: note: place parentheses around the '&amp;' expression to silence this warning
      fd_change (EV_A_ fd, w-&gt;events &amp; EV__IOFDSET | EV_ANFD_REIFY);
                                     ^
                           (                      )
    libev/ev.c:3687:3: warning: unused variable 'ocur_' [-Wunused-variable]
      array_needsize (ANHE, timers, timermax, ev_active (w) + 1, EMPTY2);
      ^
    libev/ev.c:1758:22: note: expanded from macro 'array_needsize'
          int ecb_unused ocur_ = (cur);                                     \
                         ^
    libev/ev.c:4367:5: warning: unused variable 'ocur_' [-Wunused-variable]
        array_needsize (ev_idle *, idles [ABSPRI (w)], idlemax [ABSPRI (w)], active, EMPTY2);
        ^
    libev/ev.c:1758:22: note: expanded from macro 'array_needsize'
          int ecb_unused ocur_ = (cur);                                     \
                         ^
    libev/ev.c:4407:3: warning: unused variable 'ocur_' [-Wunused-variable]
      array_needsize (ev_prepare *, prepares, preparemax, preparecnt, EMPTY2);
      ^
    libev/ev.c:1758:22: note: expanded from macro 'array_needsize'
          int ecb_unused ocur_ = (cur);                                     \
                         ^
    libev/ev.c:4445:3: warning: unused variable 'ocur_' [-Wunused-variable]
      array_needsize (ev_check *, checks, checkmax, checkcnt, EMPTY2);
      ^
    libev/ev.c:1758:22: note: expanded from macro 'array_needsize'
          int ecb_unused ocur_ = (cur);                                     \
                         ^
    libev/ev.c:4592:3: warning: unused variable 'ocur_' [-Wunused-variable]
      array_needsize (ev_fork *, forks, forkmax, forkcnt, EMPTY2);
      ^
    libev/ev.c:1758:22: note: expanded from macro 'array_needsize'
          int ecb_unused ocur_ = (cur);                                     \
                         ^
    libev/ev.c:4675:3: warning: unused variable 'ocur_' [-Wunused-variable]
      array_needsize (ev_async *, asyncs, asyncmax, asynccnt, EMPTY2);
      ^
    libev/ev.c:1758:22: note: expanded from macro 'array_needsize'
          int ecb_unused ocur_ = (cur);                                     \
                         ^
    14 warnings and 1 error generated.
    error: command 'clang' failed with exit status 1
  
    ----------------------------------------
    Failed building wheel for gevent
  Failed to build gevent
  Installing collected packages: gevent
    Running setup.py install for gevent
      Complete output from command /usr/local/opt/python/bin/python2.7 -c "import setuptools, tokenize;__file__='/private/var/folders/q8/1c24n_wj6kzc6kgl7629pwyh0000gn/T/pip-build-3zCPVx/gevent/setup.py';exec(compile(getattr(tokenize, 'open', open)(__file__).read().replace('\r\n', '\n'), __file__, 'exec'))" install --record /var/folders/q8/1c24n_wj6kzc6kgl7629pwyh0000gn/T/pip-9VpZCX-record/install-record.txt --single-version-externally-managed --compile:
      running install
      running build
      running build_py
      running build_ext
      building 'gevent.core' extension
      clang -DNDEBUG -g -fwrapv -O3 -Wall -Wstrict-prototypes -I /opt/local/include -L /opt/local/lib -U__llvm__ -DLIBEV_EMBED=1 -DEV_COMMON= -DEV_CLEANUP_ENABLE=0 -DEV_EMBED_ENABLE=0 -DEV_PERIODIC_ENABLE=0 -Ibuild/temp.macosx-10.11-x86_64-2.7/libev -Ilibev -I/usr/local/include -I/usr/local/opt/openssl/include -I/usr/local/opt/sqlite/include -I/usr/local/Cellar/python/2.7.10_2/Frameworks/Python.framework/Versions/2.7/include/python2.7 -c gevent/gevent.core.c -o build/temp.macosx-10.11-x86_64-2.7/gevent/gevent.core.o
      clang: warning: argument unused during compilation: '-L/opt/local/lib'
      In file included from gevent/gevent.core.c:249:
      In file included from gevent/libev.h:2:
      libev/ev.c:483:48: warning: '/*' within block comment [-Wcomment]
      /*#define MIN_INTERVAL  0.00000095367431640625 /* 1/2**20, good till 2200 */
                                                     ^
      libev/ev.c:1029:42: error: '_Noreturn' keyword must precede function declarator
        ecb_inline void ecb_unreachable (void) ecb_noreturn;
                                               ^~~~~~~~~~~~
        _Noreturn
      libev/ev.c:832:26: note: expanded from macro 'ecb_noreturn'
        #define ecb_noreturn   _Noreturn
                               ^
      libev/ev.c:1625:31: warning: 'extern' variable has an initializer [-Wextern-initializer]
        EV_API_DECL struct ev_loop *ev_default_loop_ptr = 0; /* needs to be initialised to make it a definition despite extern */
                                    ^
      libev/ev.c:1796:7: warning: unused variable 'ocur_' [-Wunused-variable]
            array_needsize (ANPENDING, pendings [pri], pendingmax [pri], w_-&gt;pending, EMPTY2);
            ^
      libev/ev.c:1758:22: note: expanded from macro 'array_needsize'
            int ecb_unused ocur_ = (cur);                                     \
                           ^
      libev/ev.c:1807:3: warning: unused variable 'ocur_' [-Wunused-variable]
        array_needsize (W, rfeeds, rfeedmax, rfeedcnt + 1, EMPTY2);
        ^
      libev/ev.c:1758:22: note: expanded from macro 'array_needsize'
            int ecb_unused ocur_ = (cur);                                     \
                           ^
      libev/ev.c:1934:7: warning: unused variable 'ocur_' [-Wunused-variable]
            array_needsize (int, fdchanges, fdchangemax, fdchangecnt, EMPTY2);
            ^
      libev/ev.c:1758:22: note: expanded from macro 'array_needsize'
            int ecb_unused ocur_ = (cur);                                     \
                           ^
      In file included from gevent/gevent.core.c:249:
      In file included from gevent/libev.h:2:
      In file included from libev/ev.c:2484:
      libev/ev_kqueue.c:50:3: warning: unused variable 'ocur_' [-Wunused-variable]
        array_needsize (struct kevent, kqueue_changes, kqueue_changemax, kqueue_changecnt, EMPTY2);
        ^
      libev/ev.c:1758:22: note: expanded from macro 'array_needsize'
            int ecb_unused ocur_ = (cur);                                     \
                           ^
      In file included from gevent/gevent.core.c:249:
      In file included from gevent/libev.h:2:
      In file included from libev/ev.c:2490:
      libev/ev_poll.c:66:7: warning: unused variable 'ocur_' [-Wunused-variable]
            array_needsize (struct pollfd, polls, pollmax, pollcnt, EMPTY2);
            ^
      libev/ev.c:1758:22: note: expanded from macro 'array_needsize'
            int ecb_unused ocur_ = (cur);                                     \
                           ^
      libev/ev.c:3648:34: warning: '&amp;' within '|' [-Wbitwise-op-parentheses]
        fd_change (EV_A_ fd, w-&gt;events &amp; EV__IOFDSET | EV_ANFD_REIFY);
                             ~~~~~~~~~~^~~~~~~~~~~~~ ~
      libev/ev.c:3648:34: note: place parentheses around the '&amp;' expression to silence this warning
        fd_change (EV_A_ fd, w-&gt;events &amp; EV__IOFDSET | EV_ANFD_REIFY);
                                       ^
                             (                      )
      libev/ev.c:3687:3: warning: unused variable 'ocur_' [-Wunused-variable]
        array_needsize (ANHE, timers, timermax, ev_active (w) + 1, EMPTY2);
        ^
      libev/ev.c:1758:22: note: expanded from macro 'array_needsize'
            int ecb_unused ocur_ = (cur);                                     \
                           ^
      libev/ev.c:4367:5: warning: unused variable 'ocur_' [-Wunused-variable]
          array_needsize (ev_idle *, idles [ABSPRI (w)], idlemax [ABSPRI (w)], active, EMPTY2);
          ^
      libev/ev.c:1758:22: note: expanded from macro 'array_needsize'
            int ecb_unused ocur_ = (cur);                                     \
                           ^
      libev/ev.c:4407:3: warning: unused variable 'ocur_' [-Wunused-variable]
        array_needsize (ev_prepare *, prepares, preparemax, preparecnt, EMPTY2);
        ^
      libev/ev.c:1758:22: note: expanded from macro 'array_needsize'
            int ecb_unused ocur_ = (cur);                                     \
                           ^
      libev/ev.c:4445:3: warning: unused variable 'ocur_' [-Wunused-variable]
        array_needsize (ev_check *, checks, checkmax, checkcnt, EMPTY2);
        ^
      libev/ev.c:1758:22: note: expanded from macro 'array_needsize'
            int ecb_unused ocur_ = (cur);                                     \
                           ^
      libev/ev.c:4592:3: warning: unused variable 'ocur_' [-Wunused-variable]
        array_needsize (ev_fork *, forks, forkmax, forkcnt, EMPTY2);
        ^
      libev/ev.c:1758:22: note: expanded from macro 'array_needsize'
            int ecb_unused ocur_ = (cur);                                     \
                           ^
      libev/ev.c:4675:3: warning: unused variable 'ocur_' [-Wunused-variable]
        array_needsize (ev_async *, asyncs, asyncmax, asynccnt, EMPTY2);
        ^
      libev/ev.c:1758:22: note: expanded from macro 'array_needsize'
            int ecb_unused ocur_ = (cur);                                     \
                           ^
      14 warnings and 1 error generated.
      error: command 'clang' failed with exit status 1
  
      ----------------------------------------
  Command "/usr/local/opt/python/bin/python2.7 -c "import setuptools, tokenize;__file__='/private/var/folders/q8/1c24n_wj6kzc6kgl7629pwyh0000gn/T/pip-build-3zCPVx/gevent/setup.py';exec(compile(getattr(tokenize, 'open', open)(__file__).read().replace('\r\n', '\n'), __file__, 'exec'))" install --record /var/folders/q8/1c24n_wj6kzc6kgl7629pwyh0000gn/T/pip-9VpZCX-record/install-record.txt --single-version-externally-managed --compile" failed with error code 1 in /private/var/folders/q8/1c24n_wj6kzc6kgl7629pwyh0000gn/T/pip-build-3zCPVx/gevent
  </code></pre>