Example configurations for enabling stepping into .NET Core code when debugging in vscode with omnisharp-vscode. The configuration in launch.json and tasks.json is for debugging .NET Core apps. The configuration in settings.json is for debugging tests executed by omnisharp.

launch.json

{
  "version": "0.2.0",
  // omnisharp docs reference:
  //https://github.com/OmniSharp/omnisharp-vscode/wiki/Debugging-into-the-.NET-Framework-itself
  "configurations": [
    {
      "name": ".NET Core Launch (console)",
      "type": "coreclr",
      "request": "launch",
      "preLaunchTask": "build",
      "program": "${workspaceFolder}/<PATH TO APP DLL>",
      "console": "internalConsole",
      "stopAtEntry": false,
      "justMyCode": false,
      "symbolOptions": {
        "searchMicrosoftSymbolServer": true
      },
      "searchPaths": [
        "https://symbols.nuget.org/download/symbols"
      ]
      "supressJITOptimizations": true,
      "env": {
        "COMPlus_ZapDisable": "1"
      }
    }
  ]
}

settings.json

{
  // omnisharp docs reference:
  // https://github.com/OmniSharp/omnisharp-vscode/wiki/How-to-run-and-debug-unit-tests#notes
  "csharp.unitTestDebuggingOptions": {
    "justMyCode": false,
    "symbolOptions": {
      "searchMicrosoftSymbolServer": true
    },
    "searchPaths": [
      "https://symbols.nuget.org/download/symbols"
    ]
    "suppressJITOptimizations": true,
    "env": {
      "COMPlus_ZapDisable": "1"
    }
  }
}

tasks.json

{
  "version": "2.0.0",
  "tasks": [
    {
      "label": "build",
      "command": "dotnet",
      "type": "process",
      "args": [
        "build",
        "${workspaceFolder}/<PATH TO APP PROJECT>"
      ],
      "problemMatcher": "$msCompile"
    }
  ]
}