C# Intellisense partially broken

Issue Description

At some point, Intellisense partially stopped working properly in VS Code.

Steps to Reproduce

Unknown.

This is only broken on a single box. It is Windows 10 Insiders Fast Ring build 18990, with WSL 2 enabled, running the Ubuntu image.

The problem exists in all 3 forms:

1. Editing source via “Remote: WSL” (i.e., code launched from WSL shell)
2. Editing source without Remote extension, via the \\wsl$\Ubuntu share
3. Editing source via a local copy (purely Windows)

The logs here are provided from scenario 1, but the behavior seems identical across all 3.

Expected Behavior

Correct Intellisense behavior. /shrug

Actual Behavior

Currently broken behaviors include:

• No support for F12 anywhere into any linked assemblies (always returns “No definition found”)
• No parameter information when calling methods in linked assemblies
• Incorrect behavior with new C# features; for example, with <Nullable>enable</Nullable> in the CSPROJ, it will continue to issue CS8632 in-editor whenever using the nullable type decoration, and will not show in-editor errors for nullable issues (compilation required)

There may be others I’m not aware of.

Logs

OmniSharp log

Starting OmniSharp server at 10/8/2019, 9:00:36 AM Target: /home/brwilso/dev/appcenter/lib/telemetry-netcore/AppCenter.Telemetry.sln

OmniSharp server started with Mono 6.4.0. Path: /home/brwilso/.vscode-server/extensions/ms-vscode.csharp-1.21.4/.omnisharp/1.34.4/omnisharp/OmniSharp.exe PID: 1843

C# log

This is empty.

Environment information

VSCode version: 1.38.1 C# Extension: 1.21.4

Mono Information

OmniSharp using global mono :6.4.0

Dotnet Information

.NET Core SDK (reflecting any global.json): Version: 3.0.100 Commit: 04339c3a26

Runtime Environment: OS Name: ubuntu OS Version: 18.04 OS Platform: Linux RID: ubuntu.18.04-x64 Base Path: /usr/share/dotnet/sdk/3.0.100/

Host (useful for support): Version: 3.0.0 Commit: 95a0a61858

.NET Core SDKs installed: 2.1.802 [/usr/share/dotnet/sdk] 2.2.402 [/usr/share/dotnet/sdk] 3.0.100 [/usr/share/dotnet/sdk]

.NET Core runtimes installed: Microsoft.AspNetCore.All 2.1.13 [/usr/share/dotnet/shared/Microsoft.AspNetCore.All] Microsoft.AspNetCore.All 2.2.7 [/usr/share/dotnet/shared/Microsoft.AspNetCore.All] Microsoft.AspNetCore.App 2.1.13 [/usr/share/dotnet/shared/Microsoft.AspNetCore.App] Microsoft.AspNetCore.App 2.2.7 [/usr/share/dotnet/shared/Microsoft.AspNetCore.App] Microsoft.AspNetCore.App 3.0.0 [/usr/share/dotnet/shared/Microsoft.AspNetCore.App] Microsoft.NETCore.App 2.1.13 [/usr/share/dotnet/shared/Microsoft.NETCore.App] Microsoft.NETCore.App 2.2.7 [/usr/share/dotnet/shared/Microsoft.NETCore.App] Microsoft.NETCore.App 3.0.0 [/usr/share/dotnet/shared/Microsoft.NETCore.App]

To install additional .NET Core runtimes or SDKs: https://aka.ms/dotnet-download

Visual Studio Code Extensions

Extension	Author	Version
azure-account	ms-vscode	0.8.4
azure-pipelines	ms-azure-devops	1.157.4
chat	karigari	0.22.1
code-spell-checker	streetsidesoftware	1.7.18
csharp	ms-vscode	1.21.4
docomment	k–kato	0.1.8
dotnet-test-explorer	formulahendry	0.7.1
EditorConfig	EditorConfig	0.13.0
gitlens	eamodio	10.1.0
Go	ms-vscode	0.11.7
powershell	ms-vscode	2019.9.0
python	ms-python	2019.9.34911
quokka-vscode	WallabyJs	1.0.254
ruby	rebornix	0.25.3
toggle-excluded-files	eamodio	1.6.0
vscode-docker	ms-azuretools	0.8.1
vscode-kubernetes-tools	ms-kubernetes-tools	1.0.4
vscode-typescript-tslint-plugin	ms-vscode	1.2.2
vscode-yaml	redhat	0.5.3
vsliveshare	ms-vsliveshare	1.0.905
vsliveshare-audio	ms-vsliveshare	0.1.66
vsliveshare-pack	ms-vsliveshare	0.3.3

[code1line]

• No support for F12 anywhere into any linked assemblies (always returns “No definition found”)

this is an unfortunate regression in 1.21.4 (see OmniSharp/omnisharp-roslyn#1624) It is already fixed here OmniSharp/omnisharp-roslyn#1625 There is a pre-release OmniSharp that can be used as workaround.

"omnisharp.path": "1.34.5-beta.28"

Works on Mac and Win 10! Thx!

[filipw]

• No support for F12 anywhere into any linked assemblies (always returns “No definition found”)

this is an unfortunate regression in 1.21.4 (see https://github.com/OmniSharp/omnisharp-roslyn/pull/1624) It is already fixed here https://github.com/OmniSharp/omnisharp-roslyn/pull/1625 There is a pre-release OmniSharp that can be used as workaround.

"omnisharp.path": "1.34.5-beta.28"