test changing the windows temp dir

[IanButterworth]

Adds test for #205

Should fail on windows on master

[IanButterworth]

@cderv would you be able to help get this reproducing the issue.

Also see question here #206 (comment)

[cderv]

yes, I'll try to diagnose further the issue of why /usr/bin/tar is used in my workflow. Maybe it is not the temp dir at all.

I'll look at #206 also.

[cderv]

So I spent my morning trying to understand deeper what was happening, and it was in fact an unexpected configuration and conflict between two actions:

• https://github.com/r-lib/actions/tree/v2/setup-r will modified the PATH by default to add some tools and it includes a tar
• https://github.com/julia-actions/setup-julia will use any tar found on PATH for untar from D: (RUNNER_TEMP) to C:\hostedtoolcache\windows

So if I tweak/fix the PATH before Julia setup action, I can make it work.

Workflow file if you want to try it yourself

name: test-julia-install
on: [workflow_dispatch]

jobs:
  install:
    runs-on: windows-latest
    name: Test Julia install on windows
    steps:
      - uses: actions/checkout@v4
      - run: $env:PATH -Split ";"
        shell: powershell
      - run: gcm tar
        shell: powershell
      - uses: r-lib/actions/setup-r@v2
        # uncomment the following line to fix julia setup 
        # but it will have side effect probably on R setup
        # with:
        #  windows-path-include-rtools: false
      - run: $env:PATH -Split ";"
        shell: powershell
      - run: gcm tar
        shell: powershell
      - uses: julia-actions/setup-julia@v1
        with:
          version: '1.10'

However, I believe it is still not ideal for julia-actions/setup-julia to use a tar that could be incompatible with the expected command

setup-julia/dist/index.js

Line 271 in a1561e9

yield exec.exec('powershell', ['-Command', `tar xf ${juliaDownloadPath} --strip-components=1 -C ${dest}`]);

• juliaDownloadPath will be in D: as it is based on RUNNER_TEMP by default through tc.downloadTool()
  

  setup-julia/dist/index.js

  Lines 234 to 236 in a1561e9

  	const juliaDownloadPath = yield retry((bail) => __awaiter(this, void 0, void 0, function* () {
  	return yield tc.downloadTool(downloadURL);
  	}), {

• dest will be a folder in the hostedtoolcache folder on C:
  

  setup-julia/dist/index.js

  Lines 429 to 439 in a1561e9

  	core.debug(`could not find Julia ${arch}/${version} in cache`);
  	// https://github.com/julia-actions/setup-julia/pull/196
  	// we want julia to be installed with unmodified file mtimes
  	// but `tc.cacheDir` uses `cp` internally which destroys mtime
  	// and `tc` provides no API to get the tool directory alone
  	// so hack it by installing a empty directory then use the path it returns
  	// and extract the archives directly to that location
  	const emptyDir = fs.mkdtempSync('empty');
  	juliaPath = yield tc.cacheDir(emptyDir, 'julia', version, arch);
  	yield installer.installJulia(juliaPath, versionInfo, version, arch);
  	core.debug(`added Julia to cache: ${juliaPath}`);

So either ensuring the right tar is used or the same drive is used could be safer.

Sorry for the trouble in the first place.

[DilumAluthge]

Should we give users the option to specify which tar to use? And then just default to the first tar in the PATH if the user doesn't specify.