vscode: Insiders failed to launch for test run using vscode-test ("Could not delete obsolete instance handle" - sock file missing?)

I don’t have repro steps for this (nor do I know how common it is), but it seems like this came up in #81652 but the issue was closed by the bot and it doesn’t seem like it was addressed.

I’m running tests on GitHub Actions - this one using macOS. I use vscode-test to run the tests like this:

const res = await vstest.runTests({
	extensionDevelopmentPath: cwd,
	extensionTestsEnv: { ...testEnv, ...env },
	extensionTestsPath: path.join(cwd, "out", "src", "test", testFolder),
	launchArgs: [
		path.isAbsolute(workspaceFolder)
			? workspaceFolder
			: path.join(cwd, "src", "test", "test_projects", workspaceFolder),
		"--user-data-dir",
		path.join(cwd, ".dart_code_test_data_dir"),
	],
	version: process.env.CODE_VERSION,
});

This is called multiple times with different testFolder and workspaceFolder params. One test run was fine, but then I got this error (which then repeated for every subsequent invocation in the same way):

2019-12-05T09:17:37.8141490Z   test environment
2019-12-05T09:17:37.8146740Z 
2019-12-05T09:17:37.8147990Z     ✓ has opened the correct folder
2019-12-05T09:17:37.8150710Z 
2019-12-05T09:17:37.8151900Z   3 passing (6s)
2019-12-05T09:17:37.8152370Z 
2019-12-05T09:17:37.8158840Z Test run is complete! Calling VS Code callback with (null, 0)
2019-12-05T09:17:37.8173710Z 
2019-12-05T09:17:40.8880150Z Exit code:   0
2019-12-05T09:17:40.8880790Z Done
2019-12-05T09:17:40.8881040Z 
2019-12-05T09:17:40.8881520Z ############################################################
2019-12-05T09:17:40.8881740Z 
2019-12-05T09:17:40.8881870Z 
2019-12-05T09:17:40.8882050Z 
2019-12-05T09:17:40.8882550Z Running not_activated/dart_create tests folder in workspace empty
2019-12-05T09:17:40.8884650Z Attempting to download VS Code attempt #1
2019-12-05T09:17:41.1385550Z Found .vscode-test/vscode-1.40.2. Skipping download.
2019-12-05T09:17:41.1386330Z Running tests with pre-downloaded VS Code
2019-12-05T09:17:41.6285570Z Found .vscode-test/vscode-insiders matching latest Insiders release. Skipping download.
2019-12-05T09:17:42.0750980Z [main 2019-12-05T09:17:42.070Z] Could not delete obsolete instance handle Error: ENOENT: no such file or directory, unlink '/Users/runner/runners/2.162.0/work/Dart-Code/Dart-Code/.dart_code_test_data_dir/1.41.0-insider-main.sock'
2019-12-05T09:17:42.0751790Z     at Object.unlinkSync (original-fs.js:976:3)
2019-12-05T09:17:42.0752680Z     at Object.doStartup (/Users/runner/runners/2.162.0/work/Dart-Code/Dart-Code/.vscode-test/vscode-insiders/Visual Studio Code - Insiders.app/Contents/Resources/app/out/vs/code/electron-main/main.js:551:165)
2019-12-05T09:17:42.0752980Z     at processTicksAndRejections (internal/process/task_queues.js:89:5) {
2019-12-05T09:17:42.0753490Z   errno: -2,
2019-12-05T09:17:42.0754000Z   syscall: 'unlink',
2019-12-05T09:17:42.0754680Z   code: 'ENOENT',
2019-12-05T09:17:42.0755420Z   path: '/Users/runner/runners/2.162.0/work/Dart-Code/Dart-Code/.dart_code_test_data_dir/1.41.0-insider-main.sock'
2019-12-05T09:17:42.0755680Z }
2019-12-05T09:17:42.0755760Z 
2019-12-05T09:17:42.0757390Z [main 2019-12-05T09:17:42.075Z] Error: ENOENT: no such file or directory, unlink '/Users/runner/runners/2.162.0/work/Dart-Code/Dart-Code/.dart_code_test_data_dir/1.41.0-insider-main.sock'
2019-12-05T09:17:42.0758040Z     at Object.unlinkSync (original-fs.js:976:3)
2019-12-05T09:17:42.0758900Z     at Object.doStartup (/Users/runner/runners/2.162.0/work/Dart-Code/Dart-Code/.vscode-test/vscode-insiders/Visual Studio Code - Insiders.app/Contents/Resources/app/out/vs/code/electron-main/main.js:551:165)
2019-12-05T09:17:42.0759230Z     at processTicksAndRejections (internal/process/task_queues.js:89:5)
2019-12-05T09:17:42.0759320Z 
2019-12-05T09:17:42.0884930Z Exit code:   1
2019-12-05T09:17:42.0886770Z Done
2019-12-05T09:17:42.0886940Z 
2019-12-05T09:17:42.0894300Z Failed
2019-12-05T09:17:42.0894790Z ############################################################
2019-12-05T09:17:42.0918950Z 

Is this something VS Code can recover better from? It’s particularly bad on GitHub Actions where it’s not possible to re-run individual steps (so I have to re-run a whole 1-hour run to retry this) - though I appreciate that’s hardly VS Code’s fault 😃