plugin host not to crash on activation error and add messages

[amiramw]

to notify the end user about plugin activation or loading errors

Signed-off-by: Amiram Wingarten amiram.wingarten@sap.com

What it does

Fixes a behavior such that exception on activatation method carshes plugin host without showing the exception anywhere which make it impossible to investigate without debugging the plugins.
Now such exception is catched, logged and message is showed to the end user.
Cover some of the issues raised in #6061

How to test

Create extension with activation event * and throw an exception on the activation method. Make sure that when loading it a proper message is printed to console and showed to the end user. Make sure that plugin host doesn't crash and that other plugins still work.

Review checklist

• as an author, I have thoroughly tested my changes and carefully followed the review guidelines

Reminder for reviewers

• as a reviewer, I agree to behave in accordance with the review guidelines

[akosyakov]

Create extension with activation event * and throw an exception on the activation method. Make sure that when loading it a proper message is printed to console and showed to the end user. Make sure that plugin host doesn't crash and that other plugins still work.

@amiramw Could you provide an extension please?

[amiramw]

@akosyakov here is an example for such problematic extension: https://github.com/amiramw/error-activate-vscode

[amiramw]

@akosyakov i believe i addressed all the comments. please review.

[akosyakov]

I've tested that dart and flutter (dependent) still can be installed together and that failing activation of extension does not break loading of other extensions. @amiramw thank you for the work!

[akosyakov]

I think it completely fixes #6061