Debugging of FAKE build scripts

We recommend Visual Studio Code with the Ionide extension for best FAKE tooling support, including proper debugging. The easiest way to debug a script is by using the "Debug" buttons in the FAKE targets outline

Non-Ionide or no Fake.Core.Targets

If you don't use Ionide or if you don't use Fake.Core.Targets the Outline stays empty and you (currently) cannot run or debug via UI. Please see the following sections on how to debug and run.

General considerations

Run with more verbose logging -v
If an error happens while restoring packages (before even running the script), consider using -vv or -v -v
to increase the logging even more.

Currently debugging via the chocolatey installation is not possible. This is because we currently do not distribute the x64 version on x64 versions of windows and the .NET Core debugger currently only supports x64!

Visual Studio Code && portable.zip

Debugging works (on windows) in the following way:

Download the portable fake distribution fake-dotnetcore-portable.zip and extract it somewhere (for example E:\fake-dotnetcore-portable)
Open Visual Studio Code

Open "The Debugger" view and add the following configuration

{
"name": "Debug My Build Script",
"type": "coreclr",
"request": "launch",
"program": "E:\\fake-dotnetcore-portable\\fake.dll",
"args": ["run", "--nocache", "--fsiargs", "--debug:portable --optimize-", "build.fsx"],
"cwd": "${workspaceRoot}",
"stopAtEntry": false,
"console": "internalConsole"
}

It is important to specify --debug:portable --optimize- To get debugging support for .NET Core you need C# for Visual Studio Code

Delete the .fake directory
Set a breakpoint in your script and run the new configuration

Visual Studio Code && `dotnet fake`

Add the following lines to your build script:

printfn "Press any key to continue..."
System.Console.ReadKey() |> ignore

Delete .fake directory
Start your build script via dotnet fake run --nocache build.fsx --fsiargs "--debug:portable --optimize-" and wait for the Press any key to continue... Message
Select ".NET Core Attach" in the Visual Studio Code Debugger View
Press play and select the dotnet exec --depsfile ".../fake..." process.

Run script without fake.exe (via fsi)

FAKE 5 and above scripts are not hardwired to the new FAKE 5 runner (even if they look like with the new header). To make them work with FSI all you need to do is to setup a "FAKE-Context":

// Regular header and `#load ".fake/build.fsx/intellisense.fsx"`

#if !FAKE
let execContext = Fake.Core.Context.FakeExecutionContext.Create false "build.fsx" []
Fake.Core.Context.setExecutionContext (Fake.Core.Context.RuntimeContext.Fake execContext)
#endif

// Your Script code...

With these lines you can just run fsi build.fsx

You can use this "trick" to run the script via the regular IDE buttons.

To start a new context or cleanup the old one you can use (execute interactively):