Could not find file default.win32manifest

[matthid]

I'm using FCS to compile something on the dotnetcore runtime for dotnetcore and get
unknown (1,1)-(1,1) parse error Could not find file 'C:\PROJ\FAKE\nuget\dotnetcore\Fake.netcore\current\default.win32manifest'.

Repro steps

let fsc = FSharpChecker.Create()
let errors, returnCode = fsc.Compile (args |> List.toArray) |> Async.RunSynchronously

Expected behavior

The compilation works

Actual behavior

unknown (1,1)-(1,1) parse error Could not find file 'C:\PROJ\FAKE\nuget\dotnetcore\Fake.netcore\current\default.win32manifest'.

Known workarounds

Copy the file from the FSharp.Compiler.Tools package to the location indicated by the error.

Question

• Why is that file needed? Can someone give a brief explanation what that is about?
• Is the FCS package missing a dependency on the FSharp.Compiler.Tools package (@cloudRoutine noticed it in the paket.dependencies of this repository)?
• Should FSharp.Compiler.Service distribute the default.win32manifest file / Is it an error in the current package?

[dsyme]

It looks like this file should be made available as part of the FSharp.Compiler.Service nuget package - though I'm not sure in which directory - and also bundled as part of the final application. On .NET Core (FX_NO_RUNTIMEENVIRONMENT) the code currently expects to find it as part of the final application. With Mono and .NET Framework the file is always part of the .NET installation itself.

#if FX_NO_RUNTIMEENVIRONMENT
                // On coreclr default manifest is alongside the compiler
                Path.Combine(System.AppContext.BaseDirectory, @"default.win32manifest")
#else
                // On the desktop default manifest is alongside the clr
                Path.Combine(System.Runtime.InteropServices.RuntimeEnvironment.GetRuntimeDirectory(), @"default.win32manifest")
#endif

There is no problem with just taking a copy of the file and including it in your application - it's never going to change. However it would be better to submit a PR to add it to the FCS package as an extra file, and then include it as a file in your application from there

It looks like these flags are also relevant for workarounds - you can specify the location directly, or say you don't want the manifest embedded

        CompilerOption("win32manifest", tagFile, OptionString (fun s -> tcConfigB.win32manifest <- s), None,
                           Some (FSComp.SR.optsWin32manifest()))
        
        CompilerOption("nowin32manifest", tagNone, OptionUnit (fun () -> tcConfigB.includewin32manifest <- false), None,
                           Some (FSComp.SR.optsNowin32manifest()))

I don't really know what the manifest resource is or does

[matthid]

Just to let others know: Slack helped me out quite a bit there.

• There is apparently the --nowin32manifest compiler option (as Don already noted) which is exactly what I need in my situation (as I only load the compiled library dynamically later)
• There is a bug open by @enricosada Embedd default.win32manifest into fsc dotnet/fsharp#1024

@baronfel (in Slack)
the file is an application manifest required to run a win32 executable. there’s one packaged by the compiler in fsc.fs, line 1035:
there’s a compiler flag to use the embedded one, or an application can provide its own (for example to opt into the HDPI-aware behavior in windows 10)

From my side the issue can be closed (if the bug from @enricosada is enough to track this) as I have a workaround for now...

[dsyme]

@matthid Thanks