"Error running command <command>: Canceled." when adding folder via extension to VS Code with folder open

[bryceitoc9]

• VSCode Version: 1.50.1
• OS Version: Windows 10 (v.1909, build 18363.1139)

Steps to Reproduce:

1. Open VS Code and open a folder. Do not create a workspace.
2. Activate an extension
3. Execute a command from the activated extension that adds a workspace folder to VS Code via the vscode.workspace.updateWorkspaceFolders call
4. Receive error notification via toast:

Error running command <command name>: Canceled. This is likely caused by the extension that contributes <command name>

5. Observe the following:

• All output channels tied to any extension are removed and appear to reboot
• Open treeviews provided by the extension don't appear to restart
• If you have an output channel tied to the extension open, the dropdown swaps to "Tasks" but the content shown in the output channel doesn't update. Clicking the dropdown and clicking another output channel loads that output channel's output correctly (including Tasks)

6. Side notes:

• If a user has no folders open, VS Code fully restarts (expected)
• If a user has a workspace open with 1+ folders (instead of just a folder open), the extension behaves as expected without the error message.

Does this issue occur when all extensions are disabled?: No, error is specifically generated by extensions adding workspace folders.

[vscodebot]

(Experimental duplicate detection)
Thanks for submitting this issue. Please also check if it is already covered by an existing one, like:

• Provide a command to open the folder or file for a specific output channel (#107571)

[bpasero]

I cannot reproduce. With a simple hello world extension, I run this code and it works fine:

vscode.workspace.updateWorkspaceFolders(0, undefined, { uri: vscode.Uri.file('/Users/bpasero/Desktop/test-ts/src/test') });

You will have to come up with minimal reproducible steps.

As for your issues pointed out in 5 and 6, could you please file individual issues so that in here we focus on the "error running command" problem?

[bryceitoc9]

This is the line in the workflow that triggers the error: https://github.com/aws/aws-toolkit-vscode/blob/master/src/lambda/commands/importLambda.ts#L97 ; unfortunately, you'll need to have an AWS account with a downloadable Lambda function to test it directly.

The helper function that that line calls is here: https://github.com/aws/aws-toolkit-vscode/blob/5d1f1807d9b9546e6ccc0ef1728d6303a6cedb89/src/shared/utilities/workspaceUtils.ts#L35

[bpasero]

I am sorry but we are not diagnosing issues in other extensions code.

[bryceitoc9]

I'll see if I can strip this out into a minimal extension, but this is definitely reproducible in this case on both Mac and Windows.

re: your test, does any code after the updateWorkspaceFolders execute?

[bpasero]

@bryceitoc9 no, it is the only code in the command. Note that we restart the extension host in certain cases and maybe that is the source of all the issues you describe? No code can execute after that if it happens.

See #69335

[bryceitoc9]

I'll see if I can play around with this in the next week or so but that does sound like it might be the root cause. 👍ed it in the meanwhile, thanks!

[bpasero]

Sounds good 👍