Re-apply problem matchers

[Gruntfuggly]

When trying to create problem matchers, it would be really handy if the problems view was refreshed when the tasks.json was saved.

[vscodebot]

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

• Option to run tasks without problem matchers or tasks.json (#62728)
• Selection of problem matcher is not very intuitive when running a task (#29562)

[justingrant]

This would be a huge help. I'm in the middle of spending multiple hours to create and troubleshoot a custom problem matcher for create-react-app. Most of that wasted time is spent closing my VSCode window or restarting the VSCode process in order to clear the problems list, because without the problems list being cleared I can't tell if the latest iteration of the problem matcher is actually working correctly (because the problems are still there even after I CTRL+C to end the npm start background task). Each restart wastes 30-60 seconds. I've had to do it 50+ times. This gets old.

In addition to refreshing problems when tasks.json is saved, I think we should also clear problems from a background task (not a non-background task though) when the task exits. The nature of a background task is that it's supposed to be running in the background. Once it's not running anymore, keeping its problems around doesn't make sense. I'd also be OK if this were an option on the task config to avoid breaking backwards compat if there are users who like the current behavior.

Finally, it would be really, really helpful if there was some kind of diagnostic option when building and troubleshooting problem matchers. When a problem isn't matched, e.g. because of an error in a regex, I have no idea which regex or config option is not working. I'd love to be able to get some sort of verbose console output or logfile that lists which regexes matched, which didn't, and any errors that happened (e.g. endsPattern or beginsPattern not matched, invalid filename, etc.)

[alexr00]

#77214 would also solve this.

[vscodebot]

Thanks for creating this issue! We figured it's covering the same as another one we already have. Thus, we closed this one as a duplicate. You can search for existing issues here. See also our issue reporting guidelines.

Happy Coding!