Allow tasks.json to generate multiline problem messages

[AshleyYakeley]

So 1.31 apparently introduces multiline messages in the problem panel. But there does not seem to be any documented way to actually generate these messages, such as in tasks.json, from arbitrary build tools.

The available documentation mentions "multiline problems", but the messages must still be each on a single line, whereas the messages I want to match are each multiline. Here's an example, from the output of the GHC compiler:

    /home/ashley/Projects/Haskell/Truth/truth-gtk/text/Main.hs:62:44: error:
        • Couldn't match expected type ‘(UISpec sel edit, Bool)
                                        -> (UISpec sel edit, Bool)’
                      with actual type ‘(UISpec sel1 tedit1, Bool)’
        • The function ‘(menuBarUISpec mbar, False)’
          is applied to one argument,
          but its type ‘(UISpec sel1 tedit1, Bool)’ has none
          In the expression: (menuBarUISpec mbar, False) (spec, True)
          In the first argument of ‘verticalUISpec’, namely
            ‘[(menuBarUISpec mbar, False) (spec, True)]’
        • Relevant bindings include
            spec :: UISpec sel edit (bound at text/Main.hs:59:50)
            simpleUI :: (UIWindow, ()) -> UISpec sel edit -> UISpec sel edit
              (bound at text/Main.hs:59:21)
       |
    62 |                         in verticalUISpec [(menuBarUISpec mbar,False)(spec,True)]
       |                                            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    

Currently the best I can do is match the first line.

[alexr00]

Info about multiline problem matchers for tasks is here: https://code.visualstudio.com/Docs/editor/tasks#_defining-a-multiline-problem-matcher

[AshleyYakeley]

This is not correct!! As I pointed out:

The available documentation mentions "multiline problems", but the messages must still be each on a single line, whereas the messages I want to match are each multiline.

[AshleyYakeley]

@alexr00 just to clarify, the documentation you point to is for multiline problems with single-line messages. The feature introduced in 1.31 is multiline problems with multi-line messages.

[alexr00]

I see. Then this is a duplicate of #9635, which we are considering adding API for.

[AshleyYakeley]

OK, it looks like you're treating the change you made in 1.31 as a partial fix to #9635, leaving that issue open until it's complete.

Thanks!