On Windows with MSYS2, I try to install jekyll:
gem install jekyll
but it fails, complaining that it can't build native extension ffi.
Looking in mkmf.log:
"pkg-config --exists libffi"
| pkg-config --libs libffi
=> "-LD:/dev/msys64/mingw64/lib/../lib -lffi\r\n"
"gcc -o conftest.exe -I/usr/include/ruby-2.3.0/x86_64-msys -I/usr/include/ruby-2.3.0/ruby/backward -I/usr/include/ruby-2.3.0 -I. -D_FORTIFY_SOURCE=2 -march=x86-64 -mtune=generic -O2 -pipe -fno-strict-aliasing conftest.c -L. -L/usr/lib -L. -pipe -fstack-protector -lruby230 -lpthread -lgmp -ldl -lcrypt "
In file included from D:/dev/msys64/usr/include/ruby-2.3.0/ruby/ruby.h:36:0,
from .../msys64/usr/include/ruby-2.3.0/ruby.h:33,
from conftest.c:1:
D:/dev/msys64/usr/include/ruby-2.3.0/ruby/defines.h:61:11: fatal error: sys/select.h: No such file or directory
What does it means exactly and how do I solve it.
