Add the optional tool-cache input, which allows the user to override the location into which Julia is installed

.github/workflows/example-builds.yml

@@ -36,11 +36,15 @@ jobs:
           npm run build
           npm run pack
 
+      - run: mkdir -p ${{ github.workspace }}/dilumtestcache # TODO: delete this line
       - name: "Set up Julia"
         id: setup-julia
         uses: ./
         with:
           version: ${{ matrix.julia-version }}
           arch: ${{ matrix.julia-arch }}
+          tool-cache: ${{ github.workspace }}/dilumtestcache # TODO: delete this line
+      - run: which julia # TODO: delete this line
+      - run: which -a julia # TODO: delete this line
       - run: julia --version
       - run: julia --compile=min -O0 -e 'import InteractiveUtils; InteractiveUtils.versioninfo()'

action.yml

@@ -1,7 +1,7 @@
 name: 'Setup Julia environment'
 description: 'Setup a Julia environment and add it to the PATH'
 author: 'Sascha Mann'
-inputs: 
+inputs:
   version:
     description: 'The Julia version to download (if necessary) and use. Example: 1.0.4'
     default: '1'
@@ -13,6 +13,10 @@ inputs:
     description: 'Display InteractiveUtils.versioninfo() after installing'
     required: false
     default: 'false'
+  tool-cache:
+    description: 'Override the value of the RUNNER_TOOL_CACHE environment variable.'
+    required: false
+    default: ''
 outputs:
   julia-version:
     description: 'The installed Julia version. May vary from the version input if a version range was given as input.'

src/setup-julia.ts

@@ -1,4 +1,14 @@
 import * as core from '@actions/core'
+
+// If we want to override the `RUNNER_TOOL_CACHE` environment variable, we need
+// to do it before we load ``@actions/tool-cache`
+const tool_cache_input_original = core.getInput('tool-cache')
+const tool_cache_input_trimmed = tool_cache_input_original.trim()
+if (tool_cache_input_trimmed.length > 0) {
+    process.env['RUNNER_TOOL_CACHE'] = tool_cache_input_trimmed
+    console.log('Overriding RUNNER_TOOL_CACHE -> ', process.env['RUNNER_TOOL_CACHE'])
+}
+
 import * as exec from '@actions/exec'
 import * as tc from '@actions/tool-cache'