The current runner (ubuntu-24.04-x64) was detected as self-hosted because the platform does not match a GitHub-hosted runner image (or that image is deprecated and no longer supported). In such a case, you should install Ruby in the $RUNNER_TOOL_CACHE yourself, for example using https://github.com/rbenv/ruby-build You can take inspiration from this workflow for more details: https://github.com/ruby/ruby-builder/blob/master/.github/workflows/build.yml $ ruby-build 3.0.6 /opt/hostedtoolcache/Ruby/3.0.6/x64 Once that completes successfully, mark it as complete with: $ touch /opt/hostedtoolcache/Ruby/3.0.6/x64.complete It is your responsibility to ensure installing Ruby like that is not done in parallel.

Error: Unknown version 3.4 for ruby on ubuntu-24.04 available versions for ruby on ubuntu-24.04: 1.9.3-p551, 2.0.0-p648, 2.1.9, 2.2.10, 2.3.0, 2.3.1, 2.3.2, 2.3.3, 2.3.4, 2.3.5, 2.3.6, 2.3.7, 2.3.8, 2.4.0, 2.4.1, 2.4.2, 2.4.3, 2.4.4, 2.4.5, 2.4.6, 2.4.7, 2.4.9, 2.4.10, 2.5.0, 2.5.1, 2.5.2, 2.5.3, 2.5.4, 2.5.5, 2.5.6, 2.5.7, 2.5.8, 2.5.9, 2.6.0, 2.6.1, 2.6.2, 2.6.3, 2.6.4, 2.6.5, 2.6.6, 2.6.7, 2.6.8, 2.6.9, 2.6.10, 2.7.0, 2.7.1, 2.7.2, 2.7.3, 2.7.4, 2.7.5, 2.7.6, 2.7.7, 2.7.8, 3.0.0-preview1, 3.0.0-preview2, 3.0.0-rc1, 3.0.0, 3.0.1, 3.0.2, 3.0.3, 3.0.4, 3.0.5, 3.0.6, 3.1.0-preview1, 3.1.0, 3.1.1, 3.1.2, 3.1.3, 3.1.4, 3.2.0-preview1, 3.2.0-preview2, 3.2.0-preview3, 3.2.0-rc1, 3.2.0, 3.2.1, 3.2.2, head, debug Make sure you use the latest version of the action with - uses: ruby/setup-ruby@v1 at validateRubyEngineAndVersion (/home/runner/work/_actions/ruby/setup-ruby/55283cc23133118229fd3f97f9336ee23a179fcf/dist/index.js:65078:13) at setupRuby (/home/runner/work/_actions/ruby/setup-ruby/55283cc23133118229fd3f97f9336ee23a179fcf/dist/index.js:64979:19) at run (/home/runner/work/_actions/ruby/setup-ruby/55283cc23133118229fd3f97f9336ee23a179fcf/dist/index.js:64946:11) at /home/runner/work/_actions/ruby/setup-ruby/55283cc23133118229fd3f97f9336ee23a179fcf/dist/index.js:65112:40 at /home/runner/work/_actions/ruby/setup-ruby/55283cc23133118229fd3f97f9336ee23a179fcf/dist/index.js:65114:3 at Object.<anonymous> (/home/runner/work/_actions/ruby/setup-ruby/55283cc23133118229fd3f97f9336ee23a179fcf/dist/index.js:65117:12) at Module._compile (node:internal/modules/cjs/loader:1529:14) at Module._extensions..js (node:internal/modules/cjs/loader:1613:10) at Module.load (node:internal/modules/cjs/loader:1275:32) at Module._load (node:internal/modules/cjs/loader:1096:12)