Download ftp.icm.edu.pl   ruby2.5-devel-2.5.9-150000.4.26.1.x86_64.rpm ftp.icm.edu.pl   ruby2.5-devel-2.5.9-150000.4.26.1.x86_64.rpm ftp.icm.edu.pl   ruby2.5-devel-2.5.9-150000.4.26.1.x86_64.rpm

Provides :
pkgconfig(ruby-2.5)
ruby2.5-devel
ruby2.5-devel(x86-64)
rubygems
rubygems_with_buildroot_patch

Requires :

/usr/bin/pkg-config
gcc
make
rpmlib(CompressedFileNames) <= 3.0.4-1
rpmlib(FileDigests) <= 4.6.0-1
rpmlib(PayloadFilesHavePrefix) <= 4.0-1
rpmlib(PayloadIsXz) <= 5.2-1
ruby2.5 = 2.5.9

Content of RPM :
/usr/include/ruby-2.5.0
/usr/include/ruby-2.5.0/ruby
/usr/include/ruby-2.5.0/ruby.h
/usr/include/ruby-2.5.0/ruby/backward
/usr/include/ruby-2.5.0/ruby/backward.h
/usr/include/ruby-2.5.0/ruby/backward/classext.h
/usr/include/ruby-2.5.0/ruby/backward/rubyio.h
/usr/include/ruby-2.5.0/ruby/backward/rubysig.h
/usr/include/ruby-2.5.0/ruby/backward/st.h
/usr/include/ruby-2.5.0/ruby/backward/util.h
/usr/include/ruby-2.5.0/ruby/debug.h
/usr/include/ruby-2.5.0/ruby/defines.h
/usr/include/ruby-2.5.0/ruby/digest.h
/usr/include/ruby-2.5.0/ruby/encoding.h
/usr/include/ruby-2.5.0/ruby/intern.h
/usr/include/ruby-2.5.0/ruby/io.h
/usr/include/ruby-2.5.0/ruby/missing.h
/usr/include/ruby-2.5.0/ruby/onigmo.h
/usr/include/ruby-2.5.0/ruby/oniguruma.h
/usr/include/ruby-2.5.0/ruby/re.h
/usr/include/ruby-2.5.0/ruby/regex.h
/usr/include/ruby-2.5.0/ruby/ruby.h
/usr/include/ruby-2.5.0/ruby/st.h
/usr/include/ruby-2.5.0/ruby/subst.h
/usr/include/ruby-2.5.0/ruby/thread.h
/usr/include/ruby-2.5.0/ruby/thread_native.h
/usr/include/ruby-2.5.0/ruby/util.h
/usr/include/ruby-2.5.0/ruby/version.h
/usr/include/ruby-2.5.0/ruby/vm.h
/usr/include/ruby-2.5.0/x86_64-linux-gnu
There is 5 files more in these RPM.