Ruby 2.5.9 is an old version that does not officially support Apple Silicon (ARM architecture). Additionally, it depends on OpenSSL 1.1, which has been disabled in Homebrew since October 2024. This means that installing Ruby 2.5.9 on a Mac M1/M2 requires a manual installation of OpenSSL 1.1, since it’s no longer available via Homebrew.
This guide will walk you through installing Ruby 2.5.9 on an Apple Silicon Mac without using Rosetta, covering OpenSSL 1.1 installation, Ruby installation using asdf
, and general compatibility notes.
Ruby 2.5.9 requires OpenSSL 1.1, but Homebrew has disabled it due to security concerns. Since newer OpenSSL versions (such as 3.x) are not compatible with Ruby 2.5.9, we must manually download, compile, and install OpenSSL 1.1.