Different behavior when running Fsc in FAKE vs fsc.exe

[pavelm]

I'm seeing an error when running the Fsc build on an fsx file, but it successfully compiles when running fsc.exe.

fsc -I:bin/Debug test.fsx
vs

[ "test.fsx" ] |> Fsc (fun p -> { p with OtherParams = [ "-I:bin/Debug" ] } )

unknown (1,1)-(1,81) typecheck error The module/namespace 'System.Runtime.CompilerServices' from compilation unit 'mscorlib' did not contain the namespace, module or type 'ExtensionAttribute'

(I am using an extension method defined in a referenced library)

Could this be a versioning issue?

[forki]

The Fsc task uses the FCS. What's inside test.fsx?

[forki]

(most people still use the MSBuild task and compile the whole fsproj or even the sln)

[pavelm]

I was able to reproduce with a simple project, see repo: https://github.com/pavelm/CompileFsx

running with FAKE triggers the problem, but using fsc.exe works fine

[pavelm]

@forki I found a work around by using the --noframework argument along with explicitly specifying the framework libraries.

    let framework = @"C:\Program Files (x86)\Reference Assemblies\Microsoft\FSharp\.NETFramework\v4.0\4.3.1.0\FSharp.Core.dll"
    let mscorlib = @"C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\.NETFramework\v4.5\mscorlib.dll"
    let system = @"C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\.NETFramework\v4.5\System.dll"
    let systemCore = @"C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\.NETFramework\v4.5\System.Core.dll"

    [file]
    |> Fsc (fun p ->
        {p with OtherParams = [ "--noframework"; "-r"; framework; "-r"; mscorlib; "-r"; system; "-r"; systemCore] } )

Seems like FSC is using an older mscorlib and/or FSharp.Core because of the ExtensionAttribute. Works fine for dlls which don't expose any extension methods.

[ghost]

I ran into the same issue, but it looks like a Fw 4.0 - 4.5 problem. i googled and found some similar issues. Is there any way to fix it without referencing an specific fsharp.core and mscorelib? I ask this 'cause when you use the --noframework you must reference other core libs like System.Numerics (also @pavelm shows us an example in the comment above) and, IMO, this add too much noise to build script files.

[matthid]

I guess the Fsc task should provide a "tool" property where you can override the executed tool (to execute an external fsc.exe instead of the bundled FCS)

[vanceism7]

I can work on this @matthid

[matthid]

@vanceism7 yes please feel free to send a pr, help is wanted on this ;)

[matthid]

As we now have the FSC module for fake 5 please report any issues the new module has