I've had some problems building older versions of Ruby with ruby-install on Archlinux. I suspect the same is happening with ruby-build. I am seeing the following after trying to install Ruby 2.1.5, 2.1.6, 2.3.0, 2.3.1, 2.3.4.
/usr/include/openssl/asn1_mac.h:10:2: error: #error "This file is obsolete; please update your software."
#error "This file is obsolete; please update your software."
or
ossl_ssl.c:465:38: error: ‘CRYPTO_LOCK_SSL_SESSION’ undeclared