Remote extension will not work if it depends on a local UI one

[tgodzik]

Does this issue occur when all extensions are disabled?: No

• VS Code Version: 1.58.0
• OS Version: Windows + WSL2

Steps to Reproduce:

1. Install Metals extension.
2. Open a WSL workspace
3. Metals will be disabled because Scala syntax extension is disabled.

It seems that if we have a remote extension and it depends on one declared as UI, VS Code will now make it disabled.
This basically, makes declaring extensionKind useless, since only workspace without it will work currently.

Any chance it can be fixed, or should we just make PR to remove extensionKind from the Scala syntax extension?

Based on discussion in #127067

[aeschli]

Yes, you can't have a (runtime) dependency from a workspace to a UI extension.

I assume you added the dependency so that when installing Metal, the user also gets scala-lang.scala.
For that you better use "extensionPack": [ "scala-lang.scala" ]

While we're at it. Yes, it would be better if scala-lang.scala doesn't define extensionKind and instead rely on our default behavior. The current setting (ui, web) will make it impossible to run it to workspace if necessary.

[tgodzik]

Any chance that this can be validated by vsce or at least have a better error? Something like The extension depends on an UI extension, which will not work on a remote machine.

[sandy081]

To confirm, this started happening after adding following support in VS Code in 1.58 - Auto disable extensions if their dependencies are disabled. It assumes that cross extension host dependencies are not supported and if an extension is disabled (for eg., by extensionKind) on a given host, then its dependents are too. So in this case, on wsl, since Scala extension is disabled (because it is UI kind), Metal extension is also disabled.

@aeschli Lets also get confirmation from @alexdima if the extensions can have cross host dependencies like this. As far as I remember we do not support this given that we do no support any cross ext host API to access other extensions API. So, it would be interesting to know how come the Metal extension got activated on remote (wsl) even when its dependency (Scala) is not enabled on the same host?

[sandy081]

@alexdima confirmed that we support cross host dependencies on following special conditions

• If the dependency is descriptive
• If the dependency supports "api": "none"

So, I think this dependency has to be supported.

Hence tagging this as a candidate.