解决方案

添加 ruby-optparse:

make menuconfig
Languages->Ruby->ruby-optparse

清理编译残留:

rm -rf staging_dir/hostpkg/lib/ruby
rm -rf staging_dir/hostpkg/include/ruby-*
rm staging_dir/hostpkg/lib/pkgconfig/ruby-*
rm staging_dir/hostpkg/bin/ruby
rm -rf build_dir/hostpkg/ruby-*

编译:

make package/feeds/packages/ruby/host/compile V=s
make package/feeds/packages/ruby/compile V=s