The openssl extension of Ruby version before 2.4 is not compatible with OpenSSL 1.1.x. At the moment, most Linux distributions that come with OpenSSL 1.1.0 have a separate package for OpenSSL 1.0.x.
On Debian 9 (stretch), it is libssl1.0-dev (note installing this would remove libssl-dev).
The openssl extension of Ruby version before 2.4 is not compatible with OpenSSL 1.1.x. At the moment, most Linux distributions that come with OpenSSL 1.1.0 have a separate package for OpenSSL 1.0.x.
On Debian 9 (stretch), it is
libssl1.0-dev
(note installing this would removelibssl-dev
).https://github.com/rbenv/ruby-build/wiki#openssl-usrincludeopensslasn1_mach102-error-error-this-file-is-obsolete-please-update-your-software