nio4r_1-x-stable_compile_warnings

mkdir -p tmp/x86_64-linux/nio4r_ext/2.4.0
cd tmp/x86_64-linux/nio4r_ext/2.4.0
/usr/local/ruby-2.4.0/bin/ruby -I. ../../../../ext/nio4r/extconf.rb
cd -
cd tmp/x86_64-linux/nio4r_ext/2.4.0
/usr/bin/gmake
../../../../ext/nio4r/monitor.c: In function ‘NIO_Monitor_initialize’:
../../../../ext/nio4r/monitor.c:103:5: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
     ev_io_init(&monitor->ev_io, NIO_Selector_monitor_callback, FPTR_TO_FD(fptr), monitor->interests);
     ^~~~~~~~~~
../../../../ext/nio4r/monitor.c:103:5: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
../../../../ext/nio4r/monitor.c:103:5: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
../../../../ext/nio4r/monitor.c:103:5: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
In file included from ../../../../ext/nio4r/nio4r_ext.c:7:0:
../../../../ext/nio4r/../libev/ev.c:488:48: warning: "/*" within comment [-Wcomment]
 /*#define MIN_INTERVAL  0.00000095367431640625 /* 1/2**20, good till 2200 */
                                                 
In file included from ../../../../ext/nio4r/nio4r_ext.c:7:0:
../../../../ext/nio4r/../libev/ev.c:1830:31: warning: ‘ev_default_loop_ptr’ initialized and declared ‘extern’
   EV_API_DECL struct ev_loop *ev_default_loop_ptr = 0; /* needs to be initialised to make it a definition despite extern */
                               ^~~~~~~~~~~~~~~~~~~
../../../../ext/nio4r/../libev/ev.c: In function ‘evpipe_init’:
../../../../ext/nio4r/../libev/ev.c:2389:3: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
   if (!ev_is_active (&pipe_w))
   ^~
In file included from ../../../../ext/nio4r/../libev/ev.c:179:0,
                 from ../../../../ext/nio4r/nio4r_ext.c:7:
../../../../ext/nio4r/../libev/ev_poll.c: In function ‘poll_poll’:
../../../../ext/nio4r/../libev/ev_poll.c:110:77: warning: left-hand operand of comma expression has no effect [-Wunused-value]
         assert (("libev: poll() returned illegal result, broken BSD kernel?", p < polls + pollcnt));
                                                                             ^
In file included from ../../../../ext/nio4r/nio4r_ext.c:7:0:
../../../../ext/nio4r/../libev/ev.c: In function ‘loop_init’:
../../../../ext/nio4r/../libev/ev.c:2918:7: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
       ev_prepare_init (&pending_w, pendingcb);
       ^~~~~~~~~~~~~~~
../../../../ext/nio4r/../libev/ev.c:2918:7: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
../../../../ext/nio4r/../libev/ev.c:2918:7: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
../../../../ext/nio4r/../libev/ev.c:2918:7: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
../../../../ext/nio4r/../libev/ev.c:2921:7: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
       ev_init (&pipe_w, pipecb);
       ^~~~~~~
../../../../ext/nio4r/../libev/ev.c:2921:7: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
../../../../ext/nio4r/../libev/ev.c:2921:7: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
../../../../ext/nio4r/../libev/ev.c:2921:7: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
../../../../ext/nio4r/../libev/ev.c:2922:7: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
       ev_set_priority (&pipe_w, EV_MAXPRI);
       ^~~~~~~~~~~~~~~
../../../../ext/nio4r/../libev/ev.c: In function ‘ev_loop_destroy’:
../../../../ext/nio4r/../libev/ev.c:2949:3: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
   if (ev_is_default_loop (EV_A) && ev_is_active (&childev))
   ^~
../../../../ext/nio4r/../libev/ev.c:2956:3: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
   if (ev_is_active (&pipe_w))
   ^~
../../../../ext/nio4r/../libev/ev.c:2966:3: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
   if (ev_is_active (&sigfd_w))
   ^~
../../../../ext/nio4r/../libev/ev.c: In function ‘loop_fork’:
../../../../ext/nio4r/../libev/ev.c:3059:3: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
   if (ev_is_active (&pipe_w) && postfork != 2)
   ^~
In file included from ../../../../ext/nio4r/../libev/ev.c:179:0,
                 from ../../../../ext/nio4r/nio4r_ext.c:7:
../../../../ext/nio4r/../libev/ev.c: In function ‘verify_watcher’:
../../../../ext/nio4r/../libev/ev.c:3101:49: warning: left-hand operand of comma expression has no effect [-Wunused-value]
   assert (("libev: watcher has invalid priority", ABSPRI (w) >= 0 && ABSPRI (w) < NUMPRI));
                                                 ^
../../../../ext/nio4r/../libev/ev.c:3104:59: warning: left-hand operand of comma expression has no effect [-Wunused-value]
     assert (("libev: pending watcher not on pending queue", pendings [ABSPRI (w)][w->pending - 1].w == w));
                                                           ^
../../../../ext/nio4r/../libev/ev.c: In function ‘verify_heap’:
../../../../ext/nio4r/../libev/ev.c:3114:54: warning: left-hand operand of comma expression has no effect [-Wunused-value]
       assert (("libev: active index mismatch in heap", ev_active (ANHE_w (heap [i])) == i));
                                                      ^
../../../../ext/nio4r/../libev/ev.c:3115:48: warning: left-hand operand of comma expression has no effect [-Wunused-value]
       assert (("libev: heap condition violated", i == HEAP0 || ANHE_at (heap [HPARENT (i)]) <= ANHE_at (heap [i])));
                                                ^
../../../../ext/nio4r/../libev/ev.c:3116:47: warning: left-hand operand of comma expression has no effect [-Wunused-value]
       assert (("libev: heap at cache mismatch", ANHE_at (heap [i]) == ev_at (ANHE_w (heap [i]))));
                                               ^
../../../../ext/nio4r/../libev/ev.c: In function ‘array_verify’:
../../../../ext/nio4r/../libev/ev.c:3127:46: warning: left-hand operand of comma expression has no effect [-Wunused-value]
       assert (("libev: active index mismatch", ev_active (ws [cnt]) == cnt + 1));
                                              ^
../../../../ext/nio4r/../libev/ev.c: In function ‘ev_verify’:
../../../../ext/nio4r/../libev/ev.c:3145:47: warning: left-hand operand of comma expression has no effect [-Wunused-value]
     assert (("libev: negative fd in fdchanges", fdchanges [i] >= 0));
                                               ^
../../../../ext/nio4r/../libev/ev.c:3158:64: warning: left-hand operand of comma expression has no effect [-Wunused-value]
               assert (("libev: io watcher list contains a loop", w != w2));
                                                                ^
../../../../ext/nio4r/../libev/ev.c:3162:61: warning: left-hand operand of comma expression has no effect [-Wunused-value]
           assert (("libev: inactive fd watcher on anfd list", ev_active (w) == 1));
                                                             ^
../../../../ext/nio4r/../libev/ev.c:3163:65: warning: left-hand operand of comma expression has no effect [-Wunused-value]
           assert (("libev: fd mismatch between watcher and anfd", ((ev_io *)w)->fd == i));
                                                                 ^
In file included from ../../../../ext/nio4r/nio4r_ext.c:7:0:
../../../../ext/nio4r/../libev/ev.c: In function ‘ev_default_loop’:
../../../../ext/nio4r/../libev/ev.c:3240:11: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
           ev_signal_init (&childev, childcb, SIGCHLD);
           ^~~~~~~~~~~~~~
../../../../ext/nio4r/../libev/ev.c:3240:11: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
../../../../ext/nio4r/../libev/ev.c:3240:11: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
../../../../ext/nio4r/../libev/ev.c:3240:11: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
../../../../ext/nio4r/../libev/ev.c:3241:11: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
           ev_set_priority (&childev, EV_MAXPRI);
           ^~~~~~~~~~~~~~~
In file included from ../../../../ext/nio4r/../libev/ev.c:179:0,
                 from ../../../../ext/nio4r/nio4r_ext.c:7:
../../../../ext/nio4r/../libev/ev.c: In function ‘timers_reify’:
../../../../ext/nio4r/../libev/ev.c:3345:93: warning: left-hand operand of comma expression has no effect [-Wunused-value]
               assert (("libev: negative ev_timer repeat value found while processing timers", w->repeat > 0.));
                                                                                             ^
../../../../ext/nio4r/../libev/ev.c: In function ‘periodics_reify’:
../../../../ext/nio4r/../libev/ev.c:3407:90: warning: left-hand operand of comma expression has no effect [-Wunused-value]
               assert (("libev: ev_periodic reschedule callback returned time in the past", ev_at (w) >= ev_rt_now));
                                                                                          ^
In file included from ../../../../ext/nio4r/nio4r_ext.c:7:0:
../../../../ext/nio4r/../libev/ev.c: In function ‘ev_backend_poll’:
../../../../ext/nio4r/../libev/ev.c:3552:1: warning: no return statement in function returning non-void [-Wreturn-type]
 }
 ^
In file included from ../../../../ext/nio4r/../libev/ev.c:179:0,
                 from ../../../../ext/nio4r/nio4r_ext.c:7:
../../../../ext/nio4r/../libev/ev.c: In function ‘ev_run’:
../../../../ext/nio4r/../libev/ev.c:3569:62: warning: left-hand operand of comma expression has no effect [-Wunused-value]
   assert (("libev: ev_loop recursion during release detected", loop_done != EVBREAK_RECURSE));
                                                              ^
In file included from ../../../../ext/nio4r/nio4r_ext.c:7:0:
../../../../ext/nio4r/../libev/ev.c:3738:36: warning: passing argument 1 of ‘rb_thread_call_without_gvl’ from incompatible pointer type [-Wincompatible-pointer-types]
         rb_thread_call_without_gvl(ev_backend_poll, (void *)&poll_args, RUBY_UBF_IO, 0);
                                    ^~~~~~~~~~~~~~~
In file included from ../../../../ext/nio4r/../libev/ev.c:42:0,
                 from ../../../../ext/nio4r/nio4r_ext.c:7:
/usr/local/ruby-2.4.0/include/ruby-2.4.0/ruby/thread.h:28:7: note: expected ‘void * (*)(void *)’ but argument is of type ‘VALUE (*)(void *) {aka long unsigned int (*)(void *)}’
 void *rb_thread_call_without_gvl(void *(*func)(void *), void *data1,
       ^~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from ../../../../ext/nio4r/nio4r_ext.c:7:0:
../../../../ext/nio4r/../libev/ev.c:3753:13: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
             assert (("libev: pipe_w not active, but pipe not written", ev_is_active (&pipe_w)));
             ^~~~~~
In file included from ../../../../ext/nio4r/../libev/ev.c:179:0,
                 from ../../../../ext/nio4r/nio4r_ext.c:7:
../../../../ext/nio4r/../libev/ev.c:3753:70: warning: left-hand operand of comma expression has no effect [-Wunused-value]
             assert (("libev: pipe_w not active, but pipe not written", ev_is_active (&pipe_w)));
                                                                      ^
../../../../ext/nio4r/../libev/ev.c: In function ‘ev_io_start’:
../../../../ext/nio4r/../libev/ev.c:3927:56: warning: left-hand operand of comma expression has no effect [-Wunused-value]
   assert (("libev: ev_io_start called with negative fd", fd >= 0));
                                                        ^
../../../../ext/nio4r/../libev/ev.c:3928:63: warning: left-hand operand of comma expression has no effect [-Wunused-value]
   assert (("libev: ev_io_start called with illegal event mask", !(w->events & ~(EV__IOFDSET | EV_READ | EV_WRITE))));
                                                               ^
../../../../ext/nio4r/../libev/ev.c:3937:62: warning: left-hand operand of comma expression has no effect [-Wunused-value]
   assert (("libev: ev_io_start called with corrupted watcher", ((WL)w)->next != (WL)w));
                                                              ^
In file included from ../../../../ext/nio4r/nio4r_ext.c:7:0:
../../../../ext/nio4r/../libev/ev.c:3939:34: warning: suggest parentheses around arithmetic in operand of ‘|’ [-Wparentheses]
   fd_change (EV_A_ fd, w->events & EV__IOFDSET | EV_ANFD_REIFY);
                        ~~~~~~~~~~^~~~~~~~~~~~~
In file included from ../../../../ext/nio4r/../libev/ev.c:179:0,
                 from ../../../../ext/nio4r/nio4r_ext.c:7:
../../../../ext/nio4r/../libev/ev.c: In function ‘ev_io_stop’:
../../../../ext/nio4r/../libev/ev.c:3952:88: warning: left-hand operand of comma expression has no effect [-Wunused-value]
   assert (("libev: ev_io_stop called with illegal fd (must stay constant after start!)", w->fd >= 0 && w->fd < anfdmax));
                                                                                        ^
../../../../ext/nio4r/../libev/ev.c: In function ‘ev_timer_start’:
../../../../ext/nio4r/../libev/ev.c:3972:75: warning: left-hand operand of comma expression has no effect [-Wunused-value]
   assert (("libev: ev_timer_start called with negative timer repeat value", w->repeat >= 0.));
                                                                           ^
../../../../ext/nio4r/../libev/ev.c: In function ‘ev_timer_stop’:
../../../../ext/nio4r/../libev/ev.c:4000:53: warning: left-hand operand of comma expression has no effect [-Wunused-value]
     assert (("libev: internal timer heap corruption", ANHE_w (timers [active]) == (WT)w));
                                                     ^
../../../../ext/nio4r/../libev/ev.c: In function ‘ev_periodic_start’:
../../../../ext/nio4r/../libev/ev.c:4062:78: warning: left-hand operand of comma expression has no effect [-Wunused-value]
       assert (("libev: ev_periodic_start called with negative interval value", w->interval >= 0.));
                                                                              ^
../../../../ext/nio4r/../libev/ev.c: In function ‘ev_periodic_stop’:
../../../../ext/nio4r/../libev/ev.c:4094:56: warning: left-hand operand of comma expression has no effect [-Wunused-value]
     assert (("libev: internal periodic heap corruption", ANHE_w (periodics [active]) == (WT)w));
                                                        ^
../../../../ext/nio4r/../libev/ev.c: In function ‘ev_signal_start’:
../../../../ext/nio4r/../libev/ev.c:4131:70: warning: left-hand operand of comma expression has no effect [-Wunused-value]
   assert (("libev: ev_signal_start called with illegal signal number", w->signum > 0 && w->signum < EV_NSIG));
                                                                      ^
../../../../ext/nio4r/../libev/ev.c:4134:73: warning: left-hand operand of comma expression has no effect [-Wunused-value]
   assert (("libev: a signal must not be attached to two different loops",
                                                                         ^
In file included from ../../../../ext/nio4r/nio4r_ext.c:7:0:
../../../../ext/nio4r/../libev/ev.c:4156:11: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
           ev_io_init (&sigfd_w, sigfdcb, sigfd, EV_READ);
           ^~~~~~~~~~
../../../../ext/nio4r/../libev/ev.c:4156:11: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
../../../../ext/nio4r/../libev/ev.c:4156:11: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
../../../../ext/nio4r/../libev/ev.c:4156:11: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
../../../../ext/nio4r/../libev/ev.c:4157:11: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
           ev_set_priority (&sigfd_w, EV_MAXPRI);
           ^~~~~~~~~~~~~~~
In file included from ../../../../ext/nio4r/../libev/ev.c:179:0,
                 from ../../../../ext/nio4r/nio4r_ext.c:7:
../../../../ext/nio4r/../libev/ev.c: In function ‘ev_child_start’:
../../../../ext/nio4r/../libev/ev.c:4252:74: warning: left-hand operand of comma expression has no effect [-Wunused-value]
   assert (("libev: child watchers are only supported in the default loop", loop == ev_default_loop_ptr));
                                                                          ^
In file included from ../../../../ext/nio4r/nio4r_ext.c:7:0:
../../../../ext/nio4r/../libev/ev.c: In function ‘infy_add’:
../../../../ext/nio4r/../libev/ev.c:4369:3: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
   if (ev_is_active (&w->timer)) ev_ref (EV_A);
   ^~
../../../../ext/nio4r/../libev/ev.c:4371:3: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
   if (ev_is_active (&w->timer)) ev_unref (EV_A);
   ^~
../../../../ext/nio4r/../libev/ev.c: In function ‘infy_init’:
../../../../ext/nio4r/../libev/ev.c:4475:7: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
       ev_io_init (&fs_w, infy_cb, fs_fd, EV_READ);
       ^~~~~~~~~~
../../../../ext/nio4r/../libev/ev.c:4475:7: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
../../../../ext/nio4r/../libev/ev.c:4475:7: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
../../../../ext/nio4r/../libev/ev.c:4475:7: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
../../../../ext/nio4r/../libev/ev.c:4476:7: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
       ev_set_priority (&fs_w, EV_MAXPRI);
       ^~~~~~~~~~~~~~~
../../../../ext/nio4r/../libev/ev.c: In function ‘infy_fork’:
../../../../ext/nio4r/../libev/ev.c:4520:15: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
               if (ev_is_active (&w->timer)) ev_ref (EV_A);
               ^~
../../../../ext/nio4r/../libev/ev.c:4522:15: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
               if (ev_is_active (&w->timer)) ev_unref (EV_A);
               ^~
../../../../ext/nio4r/../libev/ev.c: In function ‘ev_stat_start’:
../../../../ext/nio4r/../libev/ev.c:4596:3: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
   ev_timer_init (&w->timer, stat_timer_cb, 0., w->interval ? w->interval : DEF_STAT_INTERVAL);
   ^~~~~~~~~~~~~
../../../../ext/nio4r/../libev/ev.c:4596:3: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
../../../../ext/nio4r/../libev/ev.c:4596:3: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
../../../../ext/nio4r/../libev/ev.c:4596:3: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
../../../../ext/nio4r/../libev/ev.c:4596:3: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
../../../../ext/nio4r/../libev/ev.c:4597:3: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
   ev_set_priority (&w->timer, ev_priority (w));
   ^~~~~~~~~~~~~~~
../../../../ext/nio4r/../libev/ev.c: In function ‘ev_stat_stop’:
../../../../ext/nio4r/../libev/ev.c:4629:3: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
   if (ev_is_active (&w->timer))
   ^~
In file included from ../../../../ext/nio4r/../libev/ev.c:179:0,
                 from ../../../../ext/nio4r/nio4r_ext.c:7:
../../../../ext/nio4r/../libev/ev.c: In function ‘ev_embed_start’:
../../../../ext/nio4r/../libev/ev.c:4831:60: warning: left-hand operand of comma expression has no effect [-Wunused-value]
     assert (("libev: loop to be embedded is not embeddable", backend & ev_embeddable_backends ()));
                                                            ^
In file included from ../../../../ext/nio4r/nio4r_ext.c:7:0:
../../../../ext/nio4r/../libev/ev.c:4832:5: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
     ev_io_init (&w->io, embed_io_cb, backend_fd, EV_READ);
     ^~~~~~~~~~
../../../../ext/nio4r/../libev/ev.c:4832:5: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
../../../../ext/nio4r/../libev/ev.c:4832:5: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
../../../../ext/nio4r/../libev/ev.c:4832:5: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
../../../../ext/nio4r/../libev/ev.c:4837:3: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
   ev_set_priority (&w->io, ev_priority (w));
   ^~~~~~~~~~~~~~~
../../../../ext/nio4r/../libev/ev.c:4840:3: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
   ev_prepare_init (&w->prepare, embed_prepare_cb);
   ^~~~~~~~~~~~~~~
../../../../ext/nio4r/../libev/ev.c:4840:3: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
../../../../ext/nio4r/../libev/ev.c:4840:3: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
../../../../ext/nio4r/../libev/ev.c:4840:3: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
../../../../ext/nio4r/../libev/ev.c:4841:3: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
   ev_set_priority (&w->prepare, EV_MINPRI);
   ^~~~~~~~~~~~~~~
../../../../ext/nio4r/../libev/ev.c:4844:3: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
   ev_fork_init (&w->fork, embed_fork_cb);
   ^~~~~~~~~~~~
../../../../ext/nio4r/../libev/ev.c:4844:3: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
../../../../ext/nio4r/../libev/ev.c:4844:3: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
../../../../ext/nio4r/../libev/ev.c:4844:3: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
../../../../ext/nio4r/../libev/ev.c: In function ‘ev_once’:
../../../../ext/nio4r/../libev/ev.c:5054:3: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
   ev_init (&once->io, once_cb_io);
   ^~~~~~~
../../../../ext/nio4r/../libev/ev.c:5054:3: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
../../../../ext/nio4r/../libev/ev.c:5054:3: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
../../../../ext/nio4r/../libev/ev.c:5054:3: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
../../../../ext/nio4r/../libev/ev.c:5061:3: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
   ev_init (&once->to, once_cb_to);
   ^~~~~~~
../../../../ext/nio4r/../libev/ev.c:5061:3: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
../../../../ext/nio4r/../libev/ev.c:5061:3: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
../../../../ext/nio4r/../libev/ev.c:5061:3: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
       ev_timer_set (&once->to, timeout, 0.);
       ^~~~~~~~~~~~
../../../../ext/nio4r/../libev/ev.c: At top level:
../../../../ext/nio4r/../libev/ev.c:5180:27: warning: "/*" within comment [-Wcomment]
 /* EV_STAT     0x00001000 /* stat data changed */
                            
../../../../ext/nio4r/../libev/ev.c:5181:27: warning: "/*" within comment [-Wcomment]
 /* EV_EMBED    0x00010000 /* embedded event loop needs sweep */
                            
In file included from ../../../../ext/nio4r/nio4r_ext.c:7:0:
../../../../ext/nio4r/../libev/ev.c: In function ‘evpipe_write’:
../../../../ext/nio4r/../libev/ev.c:2459:11: warning: ignoring return value of ‘write’, declared with attribute warn_unused_result [-Wunused-result]
           write (evpipe [1], &counter, sizeof (uint64_t));
           ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../../../../ext/nio4r/../libev/ev.c:2471:11: warning: ignoring return value of ‘write’, declared with attribute warn_unused_result [-Wunused-result]
           write (evpipe [1], &(evpipe [1]), 1);
           ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../../../../ext/nio4r/../libev/ev.c: In function ‘pipecb’:
../../../../ext/nio4r/../libev/ev.c:2492:11: warning: ignoring return value of ‘read’, declared with attribute warn_unused_result [-Wunused-result]
           read (evpipe [1], &counter, sizeof (uint64_t));
           ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../../../../ext/nio4r/../libev/ev.c:2506:11: warning: ignoring return value of ‘read’, declared with attribute warn_unused_result [-Wunused-result]
           read (evpipe [0], &dummy, sizeof (dummy));
           ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../../../../ext/nio4r/selector.c: In function ‘NIO_Selector_allocate’:
../../../../ext/nio4r/selector.c:104:5: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
     ev_init(&selector->timer, NIO_Selector_timeout_callback);
     ^~~~~~~
../../../../ext/nio4r/selector.c:104:5: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
../../../../ext/nio4r/selector.c:104:5: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
../../../../ext/nio4r/selector.c:104:5: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
../../../../ext/nio4r/selector.c:109:5: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
     ev_io_init(&selector->wakeup, NIO_Selector_wakeup_callback, selector->wakeup_reader, EV_READ);
     ^~~~~~~~~~
../../../../ext/nio4r/selector.c:109:5: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
../../../../ext/nio4r/selector.c:109:5: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
../../../../ext/nio4r/selector.c:109:5: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
../../../../ext/nio4r/selector.c: In function ‘NIO_Selector_wakeup’:
../../../../ext/nio4r/selector.c:400:5: warning: ignoring return value of ‘write’, declared with attribute warn_unused_result [-Wunused-result]
     write(selector->wakeup_writer, "\0", 1);
     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
cd -
mkdir -p tmp/x86_64-linux/stage/lib
install -c tmp/x86_64-linux/nio4r_ext/2.4.0/nio4r_ext.so lib/nio4r_ext.so
cp tmp/x86_64-linux/nio4r_ext/2.4.0/nio4r_ext.so tmp/x86_64-linux/stage/lib/nio4r_ext.so