error FS0193 when using FAKE with a .NET 4.0 solution

[panesofglass]

I get this with both Frack and Cashel:

FakePath: .\tools\FAKE\FakeLib.dll
FAKE - F# Make - Version 1.42.32.0
LocalBuild
FAKE Arguments:
("build.fsx", "1")

FSI-Path: .\lib\FSharp\fsi.exe
MSBuild-Path: c:\Windows\Microsoft.NET\Framework\v4.0.30319\MSBuild.exe
Running Buildscript: build.fsx


error FS0193: internal error: Value cannot be null.
Parameter name: con
Press any key to continue . . .

[forki]

How can I reproduce the error? The last Frack master works on my machine.

[panesofglass]

Try the latest Cashel async at https://github.com/panesofglass/cashel/tree/async

[forki]

Cashel also works fine. I updated NUnit and the build runs.

That's weird.

[forki]

It even works on http://teamcity.codebetter.com/viewType.html?buildTypeId=bt322&tab=buildTypeStatusDiv

[forki]

Seems Frack is also working on http://teamcity.codebetter.com/viewType.html?buildTypeId=bt323&tab=buildTypeStatusDiv

[panesofglass]

Well, so long as it works elsewhere. Could be something janky on my machine. Thanks for looking into it.

[forki]

getting the same error message. Let's dig deeper

[forki]

#I @"..\tools\FAKE"
#r "FakeLib.dll"

open Fake

let f() = MSpec (fun p -> {p with HtmlOutputDir = "blub" }) []

printfn "Ready."

if I run this inside the fsi I get:

error FS0193: internal error: Value cannot be null.
Parameter name: con

The problem is the (fun p -> {p with HtmlOutputDir = "blub" }) part. Replacing this with id gives "Ready."

• This problem occurs only on a pc where FSharp was not installed and the fsi folder was copied from another PC.
• The problem occurs only if I use a record that is defined in a dll (here FakeLib.dll). If I define the record in the script it works as expected.

[forki]

I filed a bug at fsbugs.

The workaround is:
#r @"..\tools\FAKE\FakeLib.dll"

This prevents the fsi from reloading the FSharp.Core from tools\FAKE.