Vscode-powershell: Terminated due to an error (PowerShell Preview 7.1)

[PrzemyslawKlys]

Issue Description

I am experiencing a problem with...

Crashes pretty often on code that normally works fine on PowerShell 5.1

Attached Logs

Follow the instructions in the README about
capturing and sending logs.

1599205059-7015219d-fc87-4e0d-be85-0b4fdefd29921599158419835.zip

Environment Information

Visual Studio Code

| Name | Version |
| --- | --- |
| Operating System | Windows_NT x64 10.0.19042 |
| VSCode | 1.48.2|
| PowerShell Extension Version | 2020.7.0 |

PowerShell Information

|Name|Value|
|---|---|
|PSVersion|7.1.0-preview.6|
|PSEdition|Core|
|GitCommitId|7.1.0-preview.6|
|OS|Microsoft Windows 10.0.19042|
|Platform|Win32NT|
|PSCompatibleVersions|1.0 2.0 3.0 4.0 5.0 5.1.10032.0 6.0.0 6.1.0 6.2.0 7.0.0 7.1.0-preview.6|
|PSRemotingProtocolVersion|2.3|
|SerializationVersion|1.1.0.1|
|WSManStackVersion|3.0|

Visual Studio Code Extensions

Visual Studio Code Extensions(Click to Expand)

|Extension|Author|Version|
|---|---|---|
|better-toml|bungcip|0.3.2|
|bracket-pair-colorizer-2|CoenraadS|0.2.0|
|errorlens|usernamehw|3.2.1|
|format-selection-as-html|adrianwilczynski|2.3.0|
|github-linker|gimenete|0.2.3|
|gitlens|eamodio|10.2.2|
|line-endings|steditor|1.0.3|
|markdown-all-in-one|yzhang|3.3.0|
|material-icon-theme|PKief|4.2.0|
|open-in-browser|techer|2.0.0|
|powershell-preview|ms-vscode|2020.7.0|
|project-manager|alefragnani|11.2.0|
|run-in-powershell|tobysmith568|1.1.0|
|vscode-markdownlint|DavidAnson|0.36.3|
|vscode-toggle-quotes|BriteSnow|0.3.3|
|vscode-wakatime|WakaTime|4.0.7|
|vscode-yaml|redhat|0.10.1|
|xml|DotJoshJohnson|2.5.1|

[SydneyhSmith]

Thanks @PrzemyslawKlys we are working on a preview release right now and then will give this another look, once we have those fixes out

[SydneyhSmith]

Thanks for your patience, the new preview release is out and we think it solves this issue--when you have a chance would you mind giving it a try and letting us know? Thanks!

[PrzemyslawKlys]

Still there:

1600376767-94cf5bad-3b86-450a-9064-eaf9146c23271600368026495.zip

[rjmholt]

Ah now we have a stack trace!

But it's not an encouraging stack trace. Indicates a race occurring probably due to a bad registration somewhere...

[SydneyhSmith]

Likely not related but looks like this stack trace is occurring repeatedly:

System.ArgumentNullException: Pipeline response (OmniSharp.Extensions.LanguageServer.Protocol.Models.Hover) must not be null (Parameter 'request')
   at OmniSharp.Extensions.JsonRpc.Pipelines.ResponseMustNotBeNullProcessor`2.Process(T request, R response, CancellationToken cancellationToken)
   at MediatR.Pipeline.RequestPostProcessorBehavior`2.Handle(TRequest request, CancellationToken cancellationToken, RequestHandlerDelegate`1 next)
   at MediatR.Pipeline.RequestPreProcessorBehavior`2.Handle(TRequest request, CancellationToken cancellationToken, RequestHandlerDelegate`1 next)
   at OmniSharp.Extensions.LanguageServer.Server.Pipelines.ResolveCommandPipeline`2.Handle(TRequest request, CancellationToken cancellationToken, RequestHandlerDelegate`1 next)
   at OmniSharp.Extensions.JsonRpc.RequestRouterBase`1.RouteRequest(TDescriptor descriptor, Request request, CancellationToken token)
   at OmniSharp.Extensions.JsonRpc.InputHandler.<>c__DisplayClass38_0.<<RouteRequest>b__5>d.MoveNext()

cc: @david-driscoll vscode might have changed the hover request FYI

[PrzemyslawKlys]

1600964135-61374922-774f-4bfd-8572-71f93b778d7d1600964134180.zip

Another log. Keep in mind that this crash is not ever X days, but we're talking every X minutes if at all. I'm unable to use PowerShell 7.1 at all in code.

[david-driscoll]

This is actually fixed in the latest version of the library, it was a bug I introduced (I got a little happy 😢 )

[PrzemyslawKlys]

Thats great. Thank you. Just wanted to make sure it's fixed before next stable release.

[SydneyhSmith]

@david-driscoll thanks, just curious what was the issue and how did you manage to fix it?

[david-driscoll]

oh I had added a IPipelineBehavior<,> that was checking for null returns... because I clearly forgot null returns were valid. It made sense at the time, but I wasn't paying attention to spec at that point.
Needless to say I was wrong and removed it.

PR where I removed them: https://github.com/OmniSharp/csharp-language-server-protocol/commit/0b9e85dc111a75578bd00103bc3c87852543d76b

[andschwa]

When #3294 is finished, this should be resolved as the preview will contain OmniSharp v0.19 with this fix.

[andschwa]

@PrzemyslawKlys can you verify that this no longer repros with the latest preview release?

[PrzemyslawKlys]

I've not seen this issuee since very long time now. Even before you "fixed it" on Apr14