Run the installer in the runner, not in the cache server

This might prevent a class of errors in Windows

On the other hand this restore the paths to what we were
using prior to introducing the caching behaviour mechanism

The important change in the commit is the use of fs.cpSync

dist/index.js

@@ -10772,16 +10772,25 @@ async function installTool(opts) {
     core.debug(`  ... it is, at ${cachePath}`)
   }
 
+  // This makes sure we run, e.g. in Windows, the installer in the runner
+  // We're not caching the install, just the downloaded tool
+  const runnerToolPath = path.join(
+    process.env.RUNNER_TEMP,
+    '.setup-beam',
+    toolName,
+  )
+  fs.cpSync(cachePath, runnerToolPath, { recursive: true })
+
   core.debug('Performing post extract operations...')
-  await platformOpts.postExtract(cachePath)
+  await platformOpts.postExtract(runnerToolPath)
 
-  core.debug(`Adding ${cachePath}'s bin to system path`)
-  const catchPathBin = path.join(cachePath, 'bin')
-  core.addPath(catchPathBin)
+  core.debug(`Adding ${runnerToolPath}' bin to system path`)
+  const runnerToolPathBin = path.join(runnerToolPath, 'bin')
+  core.addPath(runnerToolPathBin)
 
   const installDirForVarName = `INSTALL_DIR_FOR_${toolName}`.toUpperCase()
-  core.debug(`Exporting ${installDirForVarName} as ${cachePath}`)
-  core.exportVariable(installDirForVarName, cachePath)
+  core.debug(`Exporting ${installDirForVarName} as ${runnerToolPath}`)
+  core.exportVariable(installDirForVarName, runnerToolPath)
 
   core.info(`Installed ${installOpts.tool} version`)
   const [cmd, args] = platformOpts.reportVersion()

src/setup-beam.js

@@ -952,16 +952,25 @@ async function installTool(opts) {
     core.debug(`  ... it is, at ${cachePath}`)
   }
 
+  // This makes sure we run, e.g. in Windows, the installer in the runner
+  // We're not caching the install, just the downloaded tool
+  const runnerToolPath = path.join(
+    process.env.RUNNER_TEMP,
+    '.setup-beam',
+    toolName,
+  )
+  fs.cpSync(cachePath, runnerToolPath, { recursive: true })
+
   core.debug('Performing post extract operations...')
-  await platformOpts.postExtract(cachePath)
+  await platformOpts.postExtract(runnerToolPath)
 
-  core.debug(`Adding ${cachePath}'s bin to system path`)
-  const catchPathBin = path.join(cachePath, 'bin')
-  core.addPath(catchPathBin)
+  core.debug(`Adding ${runnerToolPath}' bin to system path`)
+  const runnerToolPathBin = path.join(runnerToolPath, 'bin')
+  core.addPath(runnerToolPathBin)
 
   const installDirForVarName = `INSTALL_DIR_FOR_${toolName}`.toUpperCase()
-  core.debug(`Exporting ${installDirForVarName} as ${cachePath}`)
-  core.exportVariable(installDirForVarName, cachePath)
+  core.debug(`Exporting ${installDirForVarName} as ${runnerToolPath}`)
+  core.exportVariable(installDirForVarName, runnerToolPath)
 
   core.info(`Installed ${installOpts.tool} version`)
   const [cmd, args] = platformOpts.reportVersion()