$ gem install wdm Fetching wdm-0.1.1.gem Building native extensions. This could take a while... ERROR: Error installing wdm: ERROR: Failed to build gem native extension. current directory: /home/user/.gem/ruby/2.6.0/gems/wdm-0.1.1/ext/wdm /usr/bin/ruby.exe -I /usr/share/rubygems -r ./siteconf20220128-21934-1cmfehc.rb extconf.rb checking for -lkernel32... yes checking for windows.h... yes checking for ruby.h... yes checking for HAVE_RUBY_ENCODING_H... yes checking for rb_thread_call_without_gvl()... yes creating Makefile current directory: /home/user/.gem/ruby/2.6.0/gems/wdm-0.1.1/ext/wdm make "DESTDIR=" clean rm -f rm -f wdm_ext.so *.o *.bak mkmf.log .*.time current directory: /home/user/.gem/ruby/2.6.0/gems/wdm-0.1.1/ext/wdm make "DESTDIR=" gcc -I. -I/usr/include/ruby-2.6 -I/usr/include/ruby-2.6/ruby/backward -I/usr/include/ruby-2.6 -I. -DHAVE_WINDOWS_H -DHAVE_RUBY_H -DHAVE_CONST_HAVE_RUBY_ENCODING_H -DHAVE_RB_THREAD_CALL_WITHOUT_GVL -D_XOPEN_SOURCE -D_GNU_SOURCE -ggdb -O2 -pipe -Wall -Werror=format-security -Wp,-D_FORTIFY_SOURCE=2 -fstack-protector-strong --param=ssp-buffer-size=4 -o entry.o -c entry.c gcc -I. -I/usr/include/ruby-2.6 -I/usr/include/ruby-2.6/ruby/backward -I/usr/include/ruby-2.6 -I. -DHAVE_WINDOWS_H -DHAVE_RUBY_H -DHAVE_CONST_HAVE_RUBY_ENCODING_H -DHAVE_RB_THREAD_CALL_WITHOUT_GVL -D_XOPEN_SOURCE -D_GNU_SOURCE -ggdb -O2 -pipe -Wall -Werror=format-security -Wp,-D_FORTIFY_SOURCE=2 -fstack-protector-strong --param=ssp-buffer-size=4 -o memory.o -c memory.c gcc -I. -I/usr/include/ruby-2.6 -I/usr/include/ruby-2.6/ruby/backward -I/usr/include/ruby-2.6 -I. -DHAVE_WINDOWS_H -DHAVE_RUBY_H -DHAVE_CONST_HAVE_RUBY_ENCODING_H -DHAVE_RB_THREAD_CALL_WITHOUT_GVL -D_XOPEN_SOURCE -D_GNU_SOURCE -ggdb -O2 -pipe -Wall -Werror=format-security -Wp,-D_FORTIFY_SOURCE=2 -fstack-protector-strong --param=ssp-buffer-size=4 -o monitor.o -c monitor.c gcc -I. -I/usr/include/ruby-2.6 -I/usr/include/ruby-2.6/ruby/backward -I/usr/include/ruby-2.6 -I. -DHAVE_WINDOWS_H -DHAVE_RUBY_H -DHAVE_CONST_HAVE_RUBY_ENCODING_H -DHAVE_RB_THREAD_CALL_WITHOUT_GVL -D_XOPEN_SOURCE -D_GNU_SOURCE -ggdb -O2 -pipe -Wall -Werror=format-security -Wp,-D_FORTIFY_SOURCE=2 -fstack-protector-strong --param=ssp-buffer-size=4 -o queue.o -c queue.c queue.c: In function ‘wdm_queue_item_error_new’: queue.c:28:14: warning: implicit declaration of function ‘_vscprintf’; did you mean ‘vsiprintf’? [-Wimplicit-function-declaration] 28 | length = _vscprintf(format, ap); | ^~~~~~~~~~ | vsiprintf gcc -I. -I/usr/include/ruby-2.6 -I/usr/include/ruby-2.6/ruby/backward -I/usr/include/ruby-2.6 -I. -DHAVE_WINDOWS_H -DHAVE_RUBY_H -DHAVE_CONST_HAVE_RUBY_ENCODING_H -DHAVE_RB_THREAD_CALL_WITHOUT_GVL -D_XOPEN_SOURCE -D_GNU_SOURCE -ggdb -O2 -pipe -Wall -Werror=format-security -Wp,-D_FORTIFY_SOURCE=2 -fstack-protector-strong --param=ssp-buffer-size=4 -o rb_change.o -c rb_change.c rb_change.c: In function ‘extract_absolute_path_from_notification’: rb_change.c:47:16: error: ‘_MAX_FNAME’ undeclared (first use in this function) 47 | WCHAR file[_MAX_FNAME], ext[_MAX_EXT], filename[WDM_MAX_FILENAME]; | ^~~~~~~~~~ rb_change.c:47:16: note: each undeclared identifier is reported only once for each function it appears in rb_change.c:47:33: error: ‘_MAX_EXT’ undeclared (first use in this function); did you mean ‘EN_MAXTEXT’? 47 | WCHAR file[_MAX_FNAME], ext[_MAX_EXT], filename[WDM_MAX_FILENAME]; | ^~~~~~~~ | EN_MAXTEXT rb_change.c:74:5: warning: implicit declaration of function ‘_wsplitpath’ [-Wimplicit-function-declaration] 74 | _wsplitpath(buffer, NULL, NULL, file, ext); | ^~~~~~~~~~~ rb_change.c:47:44: warning: unused variable ‘filename’ [-Wunused-variable] 47 | WCHAR file[_MAX_FNAME], ext[_MAX_EXT], filename[WDM_MAX_FILENAME]; | ^~~~~~~~ rb_change.c:47:29: warning: unused variable ‘ext’ [-Wunused-variable] 47 | WCHAR file[_MAX_FNAME], ext[_MAX_EXT], filename[WDM_MAX_FILENAME]; | ^~~ rb_change.c:47:11: warning: unused variable ‘file’ [-Wunused-variable] 47 | WCHAR file[_MAX_FNAME], ext[_MAX_EXT], filename[WDM_MAX_FILENAME]; | ^~~~ make: *** [Makefile:246: rb_change.o] Error 1 make failed, exit code 2 Gem files will remain installed in /home/user/.gem/ruby/2.6.0/gems/wdm-0.1.1 for inspection. Results logged to /home/user/.gem/ruby/2.6.0/extensions/x86_64-cygwin/2.6.0/wdm-0.1.1/gem_make.out