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{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"`ruby_library` not using specified SDK version","articleBody":"We are testing out the flow where the desired version of ruby is not installed on the host.\r\n\r\nI expect for rules_ruby to be able to install and use v2.7.6. (Note this first requires bumping the `ruby-build` version, which I created a [PR](https://github.com/bazelruby/rules_ruby/pull/147) here).\r\n\r\nWith the version specified in WORKSPACE:\r\n```\r\nload(\"@bazelruby_rules_ruby//ruby:deps.bzl\", \"rules_ruby_select_sdk\")\r\nrules_ruby_select_sdk(version = \"2.7.6\")\r\n```\r\n\r\nI can confirm that ruby interpreter that's installed to the `@org_ruby_lang_ruby_toolchain` external repository is the right version:\r\n```\r\n➜  org_ruby_lang_ruby_toolchain build/bin/ruby -v\r\nruby 2.7.6p219 (2022-04-12 revision c9c2245c0a) [arm64-darwin21]\r\n```\r\n\r\nHowever, running any `ruby_library` target i get this error on my macos:\r\n\r\n`/System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/rubygems/core_ext/kernel_require.rb:54:in 'require': incompatible library version...`\r\n\r\nI think this requires updating the way [the binary wrapper](https://github.com/bazelruby/rules_ruby/blob/master/ruby/private/binary_wrapper.tpl) is implemented, which defaults to the first ruby found in PATH today rather than the version that's specified in the SDK:\r\n\r\n```\r\n#!/usr/bin/env ruby\r\n\r\n...\r\n\r\ndef find_ruby_binary\r\n  File.join(\r\n    RbConfig::CONFIG['bindir'],\r\n    RbConfig::CONFIG['ruby_install_name'],\r\n  )\r\nend\r\n```\r\n\r\nIn fact, it looks like there was an intention to substitute `{interpreter}` [here](https://github.com/bazelruby/rules_ruby/blob/cc2f5ce961f7fa34557264dd05c7597e634f31e1/ruby/private/binary.bzl#L68) but the wrapper script template itself does not have a `{interpreter}` placeholder anywhere, which looks like a bug.","author":{"url":"https://github.com/jgao54","@type":"Person","name":"jgao54"},"datePublished":"2023-06-27T01:51:42.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":2},"url":"https://github.com/148/rules_ruby/issues/148"}