Fix #8853 (#8855)

Author: KevinRansom

src/fsharp/FSharp.DependencyManager.Nuget/FSharp.DependencyManager.ProjectFile.fs

@@ -33,6 +33,10 @@ type internal Resolution =
 
 module internal ProjectFile =
 
+    let fsxExt = ".fsx"
+
+    let csxExt = ".csx"
+
     let findLoadsFromResolutions (resolutions:Resolution[]) =
         resolutions
         |> Array.filter(fun r ->
@@ -129,7 +133,9 @@ $(POUND_R)
     <TargetFramework>$(TARGETFRAMEWORK)</TargetFramework>
     <RuntimeIdentifier>$(RUNTIMEIDENTIFIER)</RuntimeIdentifier>
     <IsPackable>false</IsPackable>
-    <DisableImplicitFSharpCoreReference>true</DisableImplicitFSharpCoreReference>
+
+    <!-- Disable automagic FSharp.Core resolution when not using with FSharp scripts -->
+    <DisableImplicitFSharpCoreReference Condition="'$(SCRIPTEXTENSION)' != '.fsx'">true</DisableImplicitFSharpCoreReference>
     <DisableImplicitSystemValueTupleReference>true</DisableImplicitSystemValueTupleReference>
     <MSBuildAllProjects>$(MSBuildAllProjects);$(MSBuildThisFileFullPath)</MSBuildAllProjects>
 

src/fsharp/FSharp.DependencyManager.Nuget/FSharp.DependencyManager.fs

@@ -37,7 +37,7 @@ module FSharpDependencyManager =
             | _ -> ()
         }
 
-    let parsePackageReference (lines: string list) =
+    let parsePackageReference scriptExt (lines: string list) =
         let mutable binLogPath = None
         let parsePackageReferenceOption (line: string) =
             let validatePackageName package packageName =
@@ -53,7 +53,8 @@ module FSharpDependencyManager =
                 | opt :: rest ->
                     let addInclude v =
                         validatePackageName v "mscorlib"
-                        validatePackageName v "FSharp.Core"
+                        if scriptExt = fsxExt then
+                            validatePackageName v "FSharp.Core"
                         validatePackageName v "System.ValueTuple"
                         validatePackageName v "NETStandard.Library"
                         Some { current with Include = v }
@@ -166,13 +167,13 @@ type FSharpDependencyManager (outputDir:string option) =
 
         let scriptExt, poundRprefix  =
             match scriptExt with
-            | ".csx" -> ".csx", "#r \"" 
-            | _ -> ".fsx", "#r @\"" 
+            | ".csx" -> csxExt, "#r \"" 
+            | _ -> fsxExt, "#r @\"" 
 
         let packageReferences, binLogPath =
             packageManagerTextLines
             |> List.ofSeq
-            |> FSharpDependencyManager.parsePackageReference
+            |> FSharpDependencyManager.parsePackageReference scriptExt
 
         let packageReferenceLines =
             packageReferences

src/fsharp/FSharp.DependencyManager.Nuget/FSharp.DependencyManager.fsi

@@ -4,7 +4,7 @@ namespace FSharp.DependencyManager.Nuget
 
 module internal FSharpDependencyManager =
     val formatPackageReference: PackageReference -> seq<string>
-    val parsePackageReference: string list -> PackageReference list * string option option
+    val parsePackageReference: scriptExt: string -> string list -> PackageReference list * string option option
 
 /// The results of ResolveDependencies
 [<Class>]