I keep having errors to install ruby etc and gem updates etc.
But I have this error. I hope someone can advise or help.
root@CORE:/var/discourse# gem install ffi -v '1.9.17’
Building native extensions. This could take a while…
ERROR: Error installing ffi:
ERROR: Failed to build gem native extension.
current directory: /var/lib/gems/2.3.0/gems/ffi-1.9.17/ext/ffi_c
/usr/bin/ruby2.3 -r ./siteconf20170124-1582-1cpcsv8.rb extconf.rb
mkmf.rb can’t find header files for ruby at /usr/lib/ruby/include/ruby.h
extconf failed, exit code 1
Gem files will remain installed in /var/lib/gems/2.3.0/gems/ffi-1.9.17 for inspection.
Results logged to /var/lib/gems/2.3.0/extensions/x86_64-linux/2.3.0/ffi-1.9.17/gem_make.out
I need to install this to rebuild the app.