gem install async 2>&1

gem_install_async

ERROR:  Error installing async:
	ERROR: Failed to build gem native extension.

    current directory: f:/windows/tools/ruby/Ruby31-x64/lib/ruby/gems/3.1.0/gems/io-event-1.0.9/ext
f:/windows/tools/ruby/Ruby31-x64/bin/ruby.exe -I f:/windows/tools/ruby/Ruby31-x64/lib/ruby/site_ruby/3.1.0 extconf.rb
checking for rb_ext_ractor_safe()... yes
checking for &rb_fiber_transfer()... yes
checking for -luring... no
checking for sys/epoll.h... no
checking for sys/event.h... no
checking for sys/eventfd.h... no
checking for rb_io_descriptor()... yes
checking for &rb_process_status_wait()... no
checking for rb_fiber_current()... yes
checking for &rb_fiber_raise()... yes
checking for ruby/io/buffer.h... yes
creating extconf.h
creating Makefile

current directory: f:/windows/tools/ruby/Ruby31-x64/lib/ruby/gems/3.1.0/gems/io-event-1.0.9/ext
make DESTDIR\= sitearchdir\=./.gem.20221101-48316-yjd1qs sitelibdir\=./.gem.20221101-48316-yjd1qs clean

current directory: f:/windows/tools/ruby/Ruby31-x64/lib/ruby/gems/3.1.0/gems/io-event-1.0.9/ext
make DESTDIR\= sitearchdir\=./.gem.20221101-48316-yjd1qs sitelibdir\=./.gem.20221101-48316-yjd1qs
generating IO_Event-x64-mingw-ucrt.def
compiling ./io/event/event.c
compiling ./io/event/selector/selector.c
./io/event/selector/selector.c:26:10: fatal error: sys/wait.h: No such file or directory
   26 | #include <sys/wait.h>
      |          ^~~~~~~~~~~~
compilation terminated.
make: *** [Makefile:246: selector.o] Error 1

make failed, exit code 2

Gem files will remain installed in f:/windows/tools/ruby/Ruby31-x64/lib/ruby/gems/3.1.0/gems/io-event-1.0.9 for inspection.
Results logged to f:/windows/tools/ruby/Ruby31-x64/lib/ruby/gems/3.1.0/extensions/x64-mingw-ucrt/3.1.0/io-event-1.0.9/gem_make.out
Temporarily enhancing PATH for MSYS/MINGW...
Building native extensions. This could take a while...