Doesn't build on Cygwin!

Administrator@Admin ~/gear-lib/build_cygwin
$ cmake ..
-- The C compiler identification is GNU 11.3.0
-- The CXX compiler identification is GNU 11.3.0
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Check for working C compiler: /usr/bin/cc - skipped
-- Detecting C compile features
-- Detecting C compile features - done
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Check for working CXX compiler: /usr/bin/c++.exe - skipped
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- ============= Compile Env =============
--  CPU Info:    x86_64
--   OS Info:    CYGWIN-3.3.6-341.x86_64
-- Host Info:    CYGWIN
-- C COMPILER:   GNU-11.3.0
-- ============= Compile Env =============
-- ============= Project Info =============
-- src directory:          /home/Administrator/gear-lib
-- binary output path:     /home/Administrator/gear-lib/build_cygwin
-- executable output path: /home/Administrator/gear-lib/build_cygwin/build/bin
-- library output path:    /home/Administrator/gear-lib/build_cygwin/build/lib
-- ============= Project Info =============
-- check env unknown CYGWIN
-- Configuring done
-- Generating done
-- Build files have been written to: /home/Administrator/gear-lib/build_cygwin

Administrator@Admin ~/gear-lib/build_cygwin
$ make -j4
[  1%] Building C object gear-lib/libposix/CMakeFiles/posix.dir/libposix.c.o
[  2%] Building C object gear-lib/libstrex/CMakeFiles/strex.dir/libstrex.c.o
[  4%] Building C object gear-lib/libdarray/CMakeFiles/darray.dir/libdarray.c.o
[  5%] Building C object gear-lib/libdict/CMakeFiles/dict.dir/libdict.c.o
[  7%] Linking C static library ../../build/lib/libposix.a
[ 10%] Building C object gear-lib/libdict/CMakeFiles/dict.dir/test_libdict.c.o
[ 10%] Building C object gear-lib/libstrex/CMakeFiles/strex.dir/test_libstrex.c.o
[ 11%] Building C object gear-lib/libdarray/CMakeFiles/darray.dir/libdstring.c.o
[ 13%] Built target posix
[ 13%] Linking C static library ../../build/lib/libstrex.a
[ 14%] Linking C static library ../../build/lib/libdict.a
[ 16%] Building C object gear-lib/libqueue/CMakeFiles/queue.dir/libqueue.c.o
[ 17%] Building C object gear-lib/libdarray/CMakeFiles/darray.dir/libserializer.c.o
[ 17%] Built target strex
[ 17%] Built target dict
/home/Administrator/gear-lib/gear-lib/libqueue/libqueue.c:31:10: fatal error: sys/eventfd.h: No such file or directory
   31 | #include <sys/eventfd.h>
      |          ^~~~~~~~~~~~~~~
compilation terminated.
make[2]: *** [gear-lib/libqueue/CMakeFiles/queue.dir/build.make:76: gear-lib/libqueue/CMakeFiles/queue.dir/libqueue.c.o] Error 1
make[1]: *** [CMakeFiles/Makefile2:487: gear-lib/libqueue/CMakeFiles/queue.dir/all] Error 2
make[1]: *** Waiting for unfinished jobs....
[ 19%] Building C object gear-lib/libdarray/CMakeFiles/darray.dir/test_libdarray.c.o
[ 20%] Building C object gear-lib/libthread/CMakeFiles/thread.dir/liblock.c.o
[ 22%] Building C object gear-lib/libgevent/CMakeFiles/gevent.dir/libgevent.c.o
[ 23%] Building C object gear-lib/libthread/CMakeFiles/thread.dir/libthread.c.o
[ 25%] Linking C static library ../../build/lib/libdarray.a
/home/Administrator/gear-lib/gear-lib/libgevent/libgevent.c: In function ‘gevent_base_create’:
/home/Administrator/gear-lib/gear-lib/libgevent/libgevent.c:116:20: warning: implicit declaration of function ‘eventfd’ [-Wimplicit-function-declaration]
  116 |     eb->inner_fd = eventfd(0, 0);
      |                    ^~~~~~~
[ 26%] Linking C static library ../../build/lib/libgevent.a
[ 28%] Linking C static library ../../build/lib/libthread.a
[ 28%] Built target darray
[ 28%] Built target gevent
[ 28%] Built target thread
make: *** [Makefile:91: all] Error 2
gozfree / gear-lib

Doesn't build on Cygwin! #80
