Also include the version in the platform for macos and windows

* Guess the platform based on $ImageOS.

README.md

@@ -21,13 +21,16 @@ This action currently supports these versions of MRI, JRuby and TruffleRuby:
 `ruby-debug` is the same as `ruby-head` but with assertions enabled (`-DRUBY_DEBUG=1`).  
 On Windows, `mingw` and `mswin` are `ruby-head` builds using the MSYS2/MinGW and the MSVC toolchains respectively.
 
+Preview and RC versions of Ruby might be available too on Ubuntu and macOS (not on Windows).
+However, it is recommended to test against `ruby-head` rather than previews,
+as it provides more useful feedback for the Ruby core team and for upcoming changes.
+
 Only versions published by [RubyInstaller](https://rubyinstaller.org/downloads/archives/) are available on Windows.
 Due to that, Ruby 2.2 resolves to 2.2.6 on Windows and 2.2.10 on other platforms.
 And Ruby 2.3 on Windows only has builds for 2.3.0, 2.3.1 and 2.3.3.
 
-Note that Ruby ≤ 2.3 and the OpenSSL version it needs (1.0.2) are both end-of-life,
-which means Ruby ≤ 2.3 is unmaintained and considered insecure.
-On Windows, Ruby 2.4 uses OpenSSL 1.0.2, which is no longer maintained.
+Note that Ruby ≤ 2.4 and the OpenSSL version it needs (1.0.2) are both end-of-life,
+which means Ruby ≤ 2.4 is unmaintained and considered insecure.
 
 ### Supported Platforms
 
@@ -200,7 +203,10 @@ if the [virtual environment](https://github.com/actions/virtual-environments) is
 * Make sure to use the same operating system and version.
 * Make sure to use the same version of libssl.
 * Make sure that the operating system has `libyaml-0` installed
-* The runner software is running as user `runner` with a home directory of `/home/runner`, or you have created a symlink for the home directory of whatever user that the runner is running as to `/home/runner`.
+* The default tool cache directory (`/opt/hostedtoolcache` on Linux, `/Users/runner/hostedtoolcache` on macOS,
+  `C:/hostedtoolcache/windows` on Windows) must be writable by the `runner` user.
+  This is necessary since the Ruby builds embed the install path when built and cannot be moved around.
+* `/home/runner` must be writable by the `runner` user.
 
 In other cases, please use a system Ruby or [install Ruby manually](https://github.com/postmodern/chruby/wiki#installing-rubies) instead.
 

common.js

@@ -36,27 +36,55 @@ export async function hashFile(file) {
   return hash.digest('hex')
 }
 
+function getImageOS() {
+  const imageOS = process.env['ImageOS']
+  if (!imageOS) {
+    throw new Error('The environment variable ImageOS must be set')
+  }
+  return imageOS
+}
+
 export function getVirtualEnvironmentName() {
-  const platform = os.platform()
-  if (platform === 'linux') {
-    return `ubuntu-${findUbuntuVersion()}`
-  } else if (platform === 'darwin') {
-    return 'macos-latest'
-  } else if (platform === 'win32') {
-    return 'windows-latest'
+  const imageOS = getImageOS()
+
+  let match = imageOS.match(/^ubuntu(\d+)/) // e.g. ubuntu18
+  if (match) {
+    return `ubuntu-${match[1]}.04`
+  }
+
+  match = imageOS.match(/^macos(\d{2})(\d+)/) // e.g. macos1015
+  if (match) {
+    return `macos-${match[1]}.${match[2]}`
+  }
+
+  match = imageOS.match(/^win(\d+)/) // e.g. win19
+  if (match) {
+    return `windows-20${match[1]}`
+  }
+
+  throw new Error(`Unknown ImageOS ${imageOS}`)
+}
+
+export function shouldExtractInToolCache(engine, version) {
+  return engine === 'ruby' && !isHeadVersion(version)
+}
+
+function getPlatformToolCache(platform) {
+  // Hardcode paths rather than using $RUNNER_TOOL_CACHE because the prebuilt Rubies cannot be moved anyway
+  if (platform.startsWith('ubuntu-')) {
+    return '/opt/hostedtoolcache'
+  } else if (platform.startsWith('macos-')) {
+    return '/Users/runner/hostedtoolcache'
+  } else if (platform.startsWith('windows-')) {
+    return 'C:/hostedtoolcache/windows'
   } else {
-    throw new Error(`Unknown platform ${platform}`)
+    throw new Error('Unknown platform')
   }
 }
 
-function findUbuntuVersion() {
-  const lsb_release = fs.readFileSync('/etc/lsb-release', 'utf8')
-  const match = lsb_release.match(/^DISTRIB_RELEASE=(\d+\.\d+)$/m)
-  if (match) {
-    return match[1]
-  } else {
-    throw new Error('Could not find Ubuntu version')
-  }
+export function getToolCacheRubyPrefix(platform, version) {
+  const toolCache = getPlatformToolCache(platform)
+  return path.join(toolCache, 'Ruby', version, 'x64')
 }
 
 // convert windows path like C:\Users\runneradmin to /c/Users/runneradmin

dist/index.js

@@ -27682,6 +27682,7 @@ const path = __webpack_require__(622)
 const cp = __webpack_require__(129)
 const core = __webpack_require__(186)
 const exec = __webpack_require__(514)
+const io = __webpack_require__(436)
 const tc = __webpack_require__(188)
 const common = __webpack_require__(390)
 const rubyInstallerVersions = __webpack_require__(223).versions
@@ -27711,7 +27712,13 @@ async function install(platform, engine, version) {
   }
   const base = url.slice(url.lastIndexOf('/') + 1, url.length - '.7z'.length)
 
-  const rubyPrefix = `${drive}:\\${base}`
+  let rubyPrefix
+  if (common.shouldExtractInToolCache(engine, version)) {
+    rubyPrefix = common.getToolCacheRubyPrefix(platform, version)
+  } else {
+    rubyPrefix = `${drive}:\\${base}`
+  }
+  const parentDir = path.dirname(rubyPrefix)
 
   let toolchainPaths = (version === 'mswin') ? await setupMSWin() : await setupMingw(version)
 
@@ -27723,7 +27730,11 @@ async function install(platform, engine, version) {
   })
 
   await common.measure('Extracting Ruby', async () =>
-    exec.exec('7z', ['x', downloadPath, `-xr!${base}\\share\\doc`, `-o${drive}:\\`], { silent: true }))
+    exec.exec('7z', ['x', downloadPath, `-xr!${base}\\share\\doc`, `-o${parentDir}`], { silent: true }))
+
+  if (base !== path.basename(rubyPrefix)) {
+    await io.mv(path.join(parentDir, base), rubyPrefix)
+  }
 
   return rubyPrefix
 }
@@ -32087,6 +32098,8 @@ __webpack_require__.r(__webpack_exports__);
 /* harmony export (binding) */ __webpack_require__.d(__webpack_exports__, "isHeadVersion", function() { return isHeadVersion; });
 /* harmony export (binding) */ __webpack_require__.d(__webpack_exports__, "hashFile", function() { return hashFile; });
 /* harmony export (binding) */ __webpack_require__.d(__webpack_exports__, "getVirtualEnvironmentName", function() { return getVirtualEnvironmentName; });
+/* harmony export (binding) */ __webpack_require__.d(__webpack_exports__, "shouldExtractInToolCache", function() { return shouldExtractInToolCache; });
+/* harmony export (binding) */ __webpack_require__.d(__webpack_exports__, "getToolCacheRubyPrefix", function() { return getToolCacheRubyPrefix; });
 /* harmony export (binding) */ __webpack_require__.d(__webpack_exports__, "win2nix", function() { return win2nix; });
 /* harmony export (binding) */ __webpack_require__.d(__webpack_exports__, "setupPath", function() { return setupPath; });
 const os = __webpack_require__(87)
@@ -32127,27 +32140,55 @@ async function hashFile(file) {
   return hash.digest('hex')
 }
 
+function getImageOS() {
+  const imageOS = process.env['ImageOS']
+  if (!imageOS) {
+    throw new Error('The environment variable ImageOS must be set')
+  }
+  return imageOS
+}
+
 function getVirtualEnvironmentName() {
-  const platform = os.platform()
-  if (platform === 'linux') {
-    return `ubuntu-${findUbuntuVersion()}`
-  } else if (platform === 'darwin') {
-    return 'macos-latest'
-  } else if (platform === 'win32') {
-    return 'windows-latest'
+  const imageOS = getImageOS()
+
+  let match = imageOS.match(/^ubuntu(\d+)/) // e.g. ubuntu18
+  if (match) {
+    return `ubuntu-${match[1]}.04`
+  }
+
+  match = imageOS.match(/^macos(\d{2})(\d+)/) // e.g. macos1015
+  if (match) {
+    return `macos-${match[1]}.${match[2]}`
+  }
+
+  match = imageOS.match(/^win(\d+)/) // e.g. win19
+  if (match) {
+    return `windows-20${match[1]}`
+  }
+
+  throw new Error(`Unknown ImageOS ${imageOS}`)
+}
+
+function shouldExtractInToolCache(engine, version) {
+  return engine === 'ruby' && !isHeadVersion(version)
+}
+
+function getPlatformToolCache(platform) {
+  // Hardcode paths rather than using $RUNNER_TOOL_CACHE because the prebuilt Rubies cannot be moved anyway
+  if (platform.startsWith('ubuntu-')) {
+    return '/opt/hostedtoolcache'
+  } else if (platform.startsWith('macos-')) {
+    return '/Users/runner/hostedtoolcache'
+  } else if (platform.startsWith('windows-')) {
+    return 'C:/hostedtoolcache/windows'
   } else {
-    throw new Error(`Unknown platform ${platform}`)
+    throw new Error('Unknown platform')
   }
 }
 
-function findUbuntuVersion() {
-  const lsb_release = fs.readFileSync('/etc/lsb-release', 'utf8')
-  const match = lsb_release.match(/^DISTRIB_RELEASE=(\d+\.\d+)$/m)
-  if (match) {
-    return match[1]
-  } else {
-    throw new Error('Could not find Ubuntu version')
-  }
+function getToolCacheRubyPrefix(platform, version) {
+  const toolCache = getPlatformToolCache(platform)
+  return path.join(toolCache, 'Ruby', version, 'x64')
 }
 
 // convert windows path like C:\Users\runneradmin to /c/Users/runneradmin
@@ -44485,6 +44526,7 @@ function getVersions(platform) {
       "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",
       "2.6.0", "2.6.1", "2.6.2", "2.6.3", "2.6.4", "2.6.5", "2.6.6",
       "2.7.0", "2.7.1", "2.7.2",
+      "3.0.0-preview1",
       "head", "debug",
     ],
     "jruby": [
@@ -51155,7 +51197,7 @@ async function setupRuby(options = {}) {
   const [engine, parsedVersion] = parseRubyEngineAndVersion(inputs['ruby-version'])
 
   let installer
-  if (platform === 'windows-latest' && engine !== 'jruby') {
+  if (platform.startsWith('windows-') && engine === 'ruby') {
     installer = __webpack_require__(216)
   } else {
     installer = __webpack_require__(974)
@@ -51191,25 +51233,15 @@ async function setupRuby(options = {}) {
   core.setOutput('ruby-prefix', rubyPrefix)
 }
 
+// The returned gemfile is guaranteed to exist, the lockfile might not exist
 function detectGemfiles() {
   const gemfilePath = process.env['BUNDLE_GEMFILE'] || 'Gemfile'
   if (fs.existsSync(gemfilePath)) {
-    const lockPath = `${gemfilePath}.lock`
-    if (fs.existsSync(lockPath)) {
-      return [gemfilePath, lockPath]
-    } else {
-      return [gemfilePath, null]
-    }
+    return [gemfilePath, `${gemfilePath}.lock`]
   }
 
-  const gemsRbPath = "gems.rb"
-  if (fs.existsSync(gemsRbPath)) {
-    const lockPath = "gems.locked"
-    if (fs.existsSync(lockPath)) {
-      return [gemsRbPath, lockPath]
-    } else {
-      return [gemsRbPath, null]
-    }
+  if (fs.existsSync("gems.rb")) {
+    return ["gems.rb", "gems.locked"]
   }
 
   return [null, null]
@@ -51242,7 +51274,7 @@ function parseRubyEngineAndVersion(rubyVersion) {
     version = rubyVersion
   } else if (!rubyVersion.includes('-')) { // myruby -> myruby-stableVersion
     engine = rubyVersion
-    version = '' // Let the logic below find the version
+    version = '' // Let the logic in validateRubyEngineAndVersion() find the version
   } else { // engine-X.Y.Z
     [engine, version] = rubyVersion.split('-', 2)
   }
@@ -51293,7 +51325,7 @@ function envPreInstall() {
 }
 
 function readBundledWithFromGemfileLock(lockFile) {
-  if (lockFile !== null) {
+  if (lockFile !== null && fs.existsSync(lockFile)) {
     const contents = fs.readFileSync(lockFile, 'utf8')
     const lines = contents.split(/\r?\n/)
     const bundledWithLine = lines.findIndex(line => /^BUNDLED WITH$/.test(line.trim()))
@@ -51311,7 +51343,7 @@ function readBundledWithFromGemfileLock(lockFile) {
 }
 
 async function installBundler(bundlerVersionInput, lockFile, platform, rubyPrefix, engine, rubyVersion) {
-  var bundlerVersion = bundlerVersionInput
+  let bundlerVersion = bundlerVersionInput
 
   if (bundlerVersion === 'default' || bundlerVersion === 'Gemfile.lock') {
     bundlerVersion = readBundledWithFromGemfileLock(lockFile)
@@ -51331,17 +51363,20 @@ async function installBundler(bundlerVersionInput, lockFile, platform, rubyPrefi
     throw new Error(`Cannot parse bundler input: ${bundlerVersion}`)
   }
 
-  if (rubyVersion.match(/^2\.[12]/)) {
+  if (engine === 'ruby' && rubyVersion.match(/^2\.[12]/)) {
     console.log('Bundler 2 requires Ruby 2.3+, using Bundler 1 on Ruby <= 2.2')
     bundlerVersion = '1'
-  } else if (rubyVersion.startsWith('2.3')) {
+  } else if (engine === 'ruby' && rubyVersion.startsWith('2.3')) {
     console.log('Ruby 2.3 has a bug with Bundler 2 (https://github.com/rubygems/rubygems/issues/3570), using Bundler 1 instead on Ruby 2.3')
     bundlerVersion = '1'
+  } else if (engine === 'jruby' && rubyVersion.startsWith('9.1.')) { // JRuby 9.1 targets Ruby 2.3, treat it the same
+    console.log('JRuby 9.1 has a bug with Bundler 2 (https://github.com/ruby/setup-ruby/issues/108), using Bundler 1 instead on JRuby 9.1')
+    bundlerVersion = '1'
   }
 
-  if (engine === 'ruby' && common.isHeadVersion(rubyVersion) && bundlerVersion === '2') {
+  if ((engine === 'ruby' || engine === 'truffleruby') && common.isHeadVersion(rubyVersion) && bundlerVersion === '2') {
     console.log(`Using Bundler 2 shipped with ${engine}-${rubyVersion}`)
-  } else if (engine === 'truffleruby' && bundlerVersion === '1') {
+  } else if (engine === 'truffleruby' && !common.isHeadVersion(rubyVersion) && bundlerVersion === '1') {
     console.log(`Using Bundler 1 shipped with ${engine}`)
   } else {
     const gem = path.join(rubyPrefix, 'bin', 'gem')
@@ -51358,24 +51393,22 @@ async function bundleInstall(gemfile, lockFile, platform, engine, version) {
   // config
   const path = 'vendor/bundle'
 
-  if (lockFile !== null) {
-    await exec.exec('bundle', ['config', '--local', 'deployment', 'true'])
-  }
   await exec.exec('bundle', ['config', '--local', 'path', path])
 
+  if (fs.existsSync(lockFile)) {
+    await exec.exec('bundle', ['config', '--local', 'deployment', 'true'])
+  } else {
+    // Generate the lockfile so we can use it to compute the cache key.
+    // This will also automatically pick up the latest gem versions compatible with the Gemfile.
+    await exec.exec('bundle', ['lock'])
+  }
+
   // cache key
   const paths = [path]
-  const baseKey = await computeBaseKey(platform, engine, version)
-  let key = baseKey
-  let restoreKeys
-  if (lockFile !== null) {
-    key += `-${lockFile}-${await common.hashFile(lockFile)}`
-    // If only Gemfile.lock we can reuse some of the cache (but it will keep old gem versions in the cache)
-    restoreKeys = [`${baseKey}-${lockFile}-`]
-  } else {
-    // Only exact key, to never mix native gems of different platforms or Ruby versions
-    restoreKeys = []
-  }
+  const baseKey = await computeBaseKey(platform, engine, version, lockFile)
+  const key = `${baseKey}-${await common.hashFile(lockFile)}`
+  // If only Gemfile.lock changes we can reuse part of the cache (but it will keep old gem versions in the cache)
+  const restoreKeys = [`${baseKey}-`]
   console.log(`Cache key: ${key}`)
 
   // restore cache & install
@@ -51394,15 +51427,11 @@ async function bundleInstall(gemfile, lockFile, platform, engine, version) {
     console.log(`Found cache for key: ${cachedKey}`)
   }
 
-  let alreadyInstalled = false
-  if (cachedKey === key) {
-    const exitCode = await exec.exec('bundle', ['check'], { ignoreReturnCode: true })
-    alreadyInstalled = (exitCode === 0)
-  }
-
-  if (!alreadyInstalled) {
-    await exec.exec('bundle', ['install', '--jobs', '4'])
+  // Always run 'bundle install' to list the gems
+  await exec.exec('bundle', ['install', '--jobs', '4'])
 
+  // @actions/cache only allows to save for non-existing keys
+  if (cachedKey !== key) {
     // Error handling from https://github.com/actions/cache/blob/master/src/save.ts
     console.log('Saving cache')
     try {
@@ -51421,8 +51450,9 @@ async function bundleInstall(gemfile, lockFile, platform, engine, version) {
   return true
 }
 
-async function computeBaseKey(platform, engine, version) {
-  let baseKey = `setup-ruby-bundle-install-${platform}-${engine}-${version}`
+async function computeBaseKey(platform, engine, version, lockFile) {
+  let key = `setup-ruby-bundler-cache-v2-${platform}-${engine}-${version}`
+
   if (engine !== 'jruby' && common.isHeadVersion(version)) {
     let revision = '';
     await exec.exec('ruby', ['-e', 'print RUBY_REVISION'], {
@@ -51433,9 +51463,11 @@ async function computeBaseKey(platform, engine, version) {
         }
       }
     });
-    baseKey += `-revision-${revision}`
+    key += `-revision-${revision}`
   }
-  return baseKey
+
+  key += `-${lockFile}`
+  return key
 }
 
 if (__filename.endsWith('index.js')) { run() }
@@ -52859,7 +52891,7 @@ const tc = __webpack_require__(188)
 const common = __webpack_require__(390)
 const rubyBuilderVersions = __webpack_require__(694)
 
-const builderReleaseTag = 'enable-shared'
+const builderReleaseTag = 'toolcache'
 const releasesURL = 'https://github.com/ruby/ruby-builder/releases'
 
 const windows = common.windows
@@ -52873,14 +52905,22 @@ async function install(platform, engine, version) {
 }
 
 async function downloadAndExtract(platform, engine, version) {
-  const rubiesDir = windows ? `${common.drive}:` : path.join(os.homedir(), '.rubies')
+  let rubyPrefix
+  if (common.shouldExtractInToolCache(engine, version)) {
+    rubyPrefix = common.getToolCacheRubyPrefix(platform, version)
+  } else if (windows) {
+    rubyPrefix = path.join(`${common.drive}:`, `${engine}-${version}`)
+  } else {
+    rubyPrefix = path.join(os.homedir(), '.rubies', `${engine}-${version}`)
+  }
 
-  const rubyPrefix = path.join(rubiesDir, `${engine}-${version}`)
+  const parentDir = path.dirname(rubyPrefix)
 
   // Set the PATH now, so the MSYS2 'tar' is in Path on Windows
   common.setupPath([path.join(rubyPrefix, 'bin')])
 
-  await io.mkdirP(rubiesDir)
+  await io.rmRF(rubyPrefix)
+  await io.mkdirP(parentDir)
 
   const downloadPath = await common.measure('Downloading Ruby', async () => {
     const url = getDownloadURL(platform, engine, version)
@@ -52891,9 +52931,9 @@ async function downloadAndExtract(platform, engine, version) {
   await common.measure('Extracting Ruby', async () => {
     if (windows) {
       // Windows 2016 doesn't have system tar, use MSYS2's, it needs unix style paths
-      await exec.exec('tar', [ '-xz', '-C', common.win2nix(rubiesDir), '-f', common.win2nix(downloadPath) ])
+      await exec.exec('tar', [ '-xz', '-C', common.win2nix(parentDir), '-f', common.win2nix(downloadPath) ])
     } else {
-      await exec.exec('tar', [ '-xz', '-C', rubiesDir, '-f',  downloadPath ])
+      await exec.exec('tar', [ '-xz', '-C', parentDir, '-f',  downloadPath ])
     }
   })
 
@@ -52901,10 +52941,17 @@ async function downloadAndExtract(platform, engine, version) {
 }
 
 function getDownloadURL(platform, engine, version) {
+  let builderPlatform = platform
+  if (platform.startsWith('windows-')) {
+    builderPlatform = 'windows-latest'
+  } else if (platform.startsWith('macos-')) {
+    builderPlatform = 'macos-latest'
+  }
+
   if (common.isHeadVersion(version)) {
-    return getLatestHeadBuildURL(platform, engine, version)
+    return getLatestHeadBuildURL(builderPlatform, engine, version)
   } else {
-    return `${releasesURL}/download/${builderReleaseTag}/${engine}-${version}-${platform}.tar.gz`
+    return `${releasesURL}/download/${builderReleaseTag}/${engine}-${version}-${builderPlatform}.tar.gz`
   }
 }
 

index.js

@@ -39,7 +39,7 @@ export async function setupRuby(options = {}) {
   const [engine, parsedVersion] = parseRubyEngineAndVersion(inputs['ruby-version'])
 
   let installer
-  if (platform === 'windows-latest' && engine !== 'jruby') {
+  if (platform.startsWith('windows-') && engine === 'ruby') {
     installer = require('./windows')
   } else {
     installer = require('./ruby-builder')
@@ -75,25 +75,15 @@ export async function setupRuby(options = {}) {
   core.setOutput('ruby-prefix', rubyPrefix)
 }
 
+// The returned gemfile is guaranteed to exist, the lockfile might not exist
 function detectGemfiles() {
   const gemfilePath = process.env['BUNDLE_GEMFILE'] || 'Gemfile'
   if (fs.existsSync(gemfilePath)) {
-    const lockPath = `${gemfilePath}.lock`
-    if (fs.existsSync(lockPath)) {
-      return [gemfilePath, lockPath]
-    } else {
-      return [gemfilePath, null]
-    }
+    return [gemfilePath, `${gemfilePath}.lock`]
   }
 
-  const gemsRbPath = "gems.rb"
-  if (fs.existsSync(gemsRbPath)) {
-    const lockPath = "gems.locked"
-    if (fs.existsSync(lockPath)) {
-      return [gemsRbPath, lockPath]
-    } else {
-      return [gemsRbPath, null]
-    }
+  if (fs.existsSync("gems.rb")) {
+    return ["gems.rb", "gems.locked"]
   }
 
   return [null, null]
@@ -126,7 +116,7 @@ function parseRubyEngineAndVersion(rubyVersion) {
     version = rubyVersion
   } else if (!rubyVersion.includes('-')) { // myruby -> myruby-stableVersion
     engine = rubyVersion
-    version = '' // Let the logic below find the version
+    version = '' // Let the logic in validateRubyEngineAndVersion() find the version
   } else { // engine-X.Y.Z
     [engine, version] = rubyVersion.split('-', 2)
   }
@@ -177,7 +167,7 @@ function envPreInstall() {
 }
 
 function readBundledWithFromGemfileLock(lockFile) {
-  if (lockFile !== null) {
+  if (lockFile !== null && fs.existsSync(lockFile)) {
     const contents = fs.readFileSync(lockFile, 'utf8')
     const lines = contents.split(/\r?\n/)
     const bundledWithLine = lines.findIndex(line => /^BUNDLED WITH$/.test(line.trim()))
@@ -195,7 +185,7 @@ function readBundledWithFromGemfileLock(lockFile) {
 }
 
 async function installBundler(bundlerVersionInput, lockFile, platform, rubyPrefix, engine, rubyVersion) {
-  var bundlerVersion = bundlerVersionInput
+  let bundlerVersion = bundlerVersionInput
 
   if (bundlerVersion === 'default' || bundlerVersion === 'Gemfile.lock') {
     bundlerVersion = readBundledWithFromGemfileLock(lockFile)
@@ -215,17 +205,20 @@ async function installBundler(bundlerVersionInput, lockFile, platform, rubyPrefi
     throw new Error(`Cannot parse bundler input: ${bundlerVersion}`)
   }
 
-  if (rubyVersion.match(/^2\.[12]/)) {
+  if (engine === 'ruby' && rubyVersion.match(/^2\.[12]/)) {
     console.log('Bundler 2 requires Ruby 2.3+, using Bundler 1 on Ruby <= 2.2')
     bundlerVersion = '1'
-  } else if (rubyVersion.startsWith('2.3')) {
+  } else if (engine === 'ruby' && rubyVersion.startsWith('2.3')) {
     console.log('Ruby 2.3 has a bug with Bundler 2 (https://github.com/rubygems/rubygems/issues/3570), using Bundler 1 instead on Ruby 2.3')
     bundlerVersion = '1'
+  } else if (engine === 'jruby' && rubyVersion.startsWith('9.1.')) { // JRuby 9.1 targets Ruby 2.3, treat it the same
+    console.log('JRuby 9.1 has a bug with Bundler 2 (https://github.com/ruby/setup-ruby/issues/108), using Bundler 1 instead on JRuby 9.1')
+    bundlerVersion = '1'
   }
 
-  if (engine === 'ruby' && common.isHeadVersion(rubyVersion) && bundlerVersion === '2') {
+  if ((engine === 'ruby' || engine === 'truffleruby') && common.isHeadVersion(rubyVersion) && bundlerVersion === '2') {
     console.log(`Using Bundler 2 shipped with ${engine}-${rubyVersion}`)
-  } else if (engine === 'truffleruby' && bundlerVersion === '1') {
+  } else if (engine === 'truffleruby' && !common.isHeadVersion(rubyVersion) && bundlerVersion === '1') {
     console.log(`Using Bundler 1 shipped with ${engine}`)
   } else {
     const gem = path.join(rubyPrefix, 'bin', 'gem')
@@ -242,24 +235,22 @@ async function bundleInstall(gemfile, lockFile, platform, engine, version) {
   // config
   const path = 'vendor/bundle'
 
-  if (lockFile !== null) {
-    await exec.exec('bundle', ['config', '--local', 'deployment', 'true'])
-  }
   await exec.exec('bundle', ['config', '--local', 'path', path])
 
+  if (fs.existsSync(lockFile)) {
+    await exec.exec('bundle', ['config', '--local', 'deployment', 'true'])
+  } else {
+    // Generate the lockfile so we can use it to compute the cache key.
+    // This will also automatically pick up the latest gem versions compatible with the Gemfile.
+    await exec.exec('bundle', ['lock'])
+  }
+
   // cache key
   const paths = [path]
-  const baseKey = await computeBaseKey(platform, engine, version)
-  let key = baseKey
-  let restoreKeys
-  if (lockFile !== null) {
-    key += `-${lockFile}-${await common.hashFile(lockFile)}`
-    // If only Gemfile.lock we can reuse some of the cache (but it will keep old gem versions in the cache)
-    restoreKeys = [`${baseKey}-${lockFile}-`]
-  } else {
-    // Only exact key, to never mix native gems of different platforms or Ruby versions
-    restoreKeys = []
-  }
+  const baseKey = await computeBaseKey(platform, engine, version, lockFile)
+  const key = `${baseKey}-${await common.hashFile(lockFile)}`
+  // If only Gemfile.lock changes we can reuse part of the cache (but it will keep old gem versions in the cache)
+  const restoreKeys = [`${baseKey}-`]
   console.log(`Cache key: ${key}`)
 
   // restore cache & install
@@ -278,15 +269,11 @@ async function bundleInstall(gemfile, lockFile, platform, engine, version) {
     console.log(`Found cache for key: ${cachedKey}`)
   }
 
-  let alreadyInstalled = false
-  if (cachedKey === key) {
-    const exitCode = await exec.exec('bundle', ['check'], { ignoreReturnCode: true })
-    alreadyInstalled = (exitCode === 0)
-  }
-
-  if (!alreadyInstalled) {
-    await exec.exec('bundle', ['install', '--jobs', '4'])
+  // Always run 'bundle install' to list the gems
+  await exec.exec('bundle', ['install', '--jobs', '4'])
 
+  // @actions/cache only allows to save for non-existing keys
+  if (cachedKey !== key) {
     // Error handling from https://github.com/actions/cache/blob/master/src/save.ts
     console.log('Saving cache')
     try {
@@ -305,8 +292,9 @@ async function bundleInstall(gemfile, lockFile, platform, engine, version) {
   return true
 }
 
-async function computeBaseKey(platform, engine, version) {
-  let baseKey = `setup-ruby-bundle-install-${platform}-${engine}-${version}`
+async function computeBaseKey(platform, engine, version, lockFile) {
+  let key = `setup-ruby-bundler-cache-v2-${platform}-${engine}-${version}`
+
   if (engine !== 'jruby' && common.isHeadVersion(version)) {
     let revision = '';
     await exec.exec('ruby', ['-e', 'print RUBY_REVISION'], {
@@ -317,9 +305,11 @@ async function computeBaseKey(platform, engine, version) {
         }
       }
     });
-    baseKey += `-revision-${revision}`
+    key += `-revision-${revision}`
   }
-  return baseKey
+
+  key += `-${lockFile}`
+  return key
 }
 
 if (__filename.endsWith('index.js')) { run() }

ruby-builder-versions.js

@@ -8,6 +8,7 @@ export function getVersions(platform) {
       "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",
       "2.6.0", "2.6.1", "2.6.2", "2.6.3", "2.6.4", "2.6.5", "2.6.6",
       "2.7.0", "2.7.1", "2.7.2",
+      "3.0.0-preview1",
       "head", "debug",
     ],
     "jruby": [

ruby-builder.js

@@ -7,7 +7,7 @@ const tc = require('@actions/tool-cache')
 const common = require('./common')
 const rubyBuilderVersions = require('./ruby-builder-versions')
 
-const builderReleaseTag = 'enable-shared'
+const builderReleaseTag = 'toolcache'
 const releasesURL = 'https://github.com/ruby/ruby-builder/releases'
 
 const windows = common.windows
@@ -21,14 +21,22 @@ export async function install(platform, engine, version) {
 }
 
 async function downloadAndExtract(platform, engine, version) {
-  const rubiesDir = windows ? `${common.drive}:` : path.join(os.homedir(), '.rubies')
+  let rubyPrefix
+  if (common.shouldExtractInToolCache(engine, version)) {
+    rubyPrefix = common.getToolCacheRubyPrefix(platform, version)
+  } else if (windows) {
+    rubyPrefix = path.join(`${common.drive}:`, `${engine}-${version}`)
+  } else {
+    rubyPrefix = path.join(os.homedir(), '.rubies', `${engine}-${version}`)
+  }
 
-  const rubyPrefix = path.join(rubiesDir, `${engine}-${version}`)
+  const parentDir = path.dirname(rubyPrefix)
 
   // Set the PATH now, so the MSYS2 'tar' is in Path on Windows
   common.setupPath([path.join(rubyPrefix, 'bin')])
 
-  await io.mkdirP(rubiesDir)
+  await io.rmRF(rubyPrefix)
+  await io.mkdirP(parentDir)
 
   const downloadPath = await common.measure('Downloading Ruby', async () => {
     const url = getDownloadURL(platform, engine, version)
@@ -39,9 +47,9 @@ async function downloadAndExtract(platform, engine, version) {
   await common.measure('Extracting Ruby', async () => {
     if (windows) {
       // Windows 2016 doesn't have system tar, use MSYS2's, it needs unix style paths
-      await exec.exec('tar', [ '-xz', '-C', common.win2nix(rubiesDir), '-f', common.win2nix(downloadPath) ])
+      await exec.exec('tar', [ '-xz', '-C', common.win2nix(parentDir), '-f', common.win2nix(downloadPath) ])
     } else {
-      await exec.exec('tar', [ '-xz', '-C', rubiesDir, '-f',  downloadPath ])
+      await exec.exec('tar', [ '-xz', '-C', parentDir, '-f',  downloadPath ])
     }
   })
 
@@ -49,10 +57,17 @@ async function downloadAndExtract(platform, engine, version) {
 }
 
 function getDownloadURL(platform, engine, version) {
+  let builderPlatform = platform
+  if (platform.startsWith('windows-')) {
+    builderPlatform = 'windows-latest'
+  } else if (platform.startsWith('macos-')) {
+    builderPlatform = 'macos-latest'
+  }
+
   if (common.isHeadVersion(version)) {
-    return getLatestHeadBuildURL(platform, engine, version)
+    return getLatestHeadBuildURL(builderPlatform, engine, version)
   } else {
-    return `${releasesURL}/download/${builderReleaseTag}/${engine}-${version}-${platform}.tar.gz`
+    return `${releasesURL}/download/${builderReleaseTag}/${engine}-${version}-${builderPlatform}.tar.gz`
   }
 }
 

windows.js

@@ -6,6 +6,7 @@ const path = require('path')
 const cp = require('child_process')
 const core = require('@actions/core')
 const exec = require('@actions/exec')
+const io = require('@actions/io')
 const tc = require('@actions/tool-cache')
 const common = require('./common')
 const rubyInstallerVersions = require('./windows-versions').versions
@@ -35,7 +36,13 @@ export async function install(platform, engine, version) {
   }
   const base = url.slice(url.lastIndexOf('/') + 1, url.length - '.7z'.length)
 
-  const rubyPrefix = `${drive}:\\${base}`
+  let rubyPrefix
+  if (common.shouldExtractInToolCache(engine, version)) {
+    rubyPrefix = common.getToolCacheRubyPrefix(platform, version)
+  } else {
+    rubyPrefix = `${drive}:\\${base}`
+  }
+  const parentDir = path.dirname(rubyPrefix)
 
   let toolchainPaths = (version === 'mswin') ? await setupMSWin() : await setupMingw(version)
 
@@ -47,7 +54,11 @@ export async function install(platform, engine, version) {
   })
 
   await common.measure('Extracting Ruby', async () =>
-    exec.exec('7z', ['x', downloadPath, `-xr!${base}\\share\\doc`, `-o${drive}:\\`], { silent: true }))
+    exec.exec('7z', ['x', downloadPath, `-xr!${base}\\share\\doc`, `-o${parentDir}`], { silent: true }))
+
+  if (base !== path.basename(rubyPrefix)) {
+    await io.mv(path.join(parentDir, base), rubyPrefix)
+  }
 
   return rubyPrefix
 }