Exit the commandline tool if the version of FSharp.Core cannot be loa…

…ded.

Directory.Packages.props

@@ -5,8 +5,8 @@
   </PropertyGroup>
   <ItemGroup>
     <PackageVersion Include="CliWrap" Version="3.6.4" />
-    <PackageVersion Include="FSharp.Core" Version="7.0.400" />
-    <PackageVersion Include="FSharp.Compiler.Service" Version="43.7.400" />
+    <PackageVersion Include="FSharp.Core" Version="[7.0.400]" />
+    <PackageVersion Include="FSharp.Compiler.Service" Version="[43.7.400]" />
     <PackageVersion Include="Ionide.KeepAChangelog.Tasks" Version="0.1.8" PrivateAssets="all" />
     <PackageVersion Include="McMaster.NETCore.Plugins" Version="1.4.0" />
     <PackageVersion Include="Argu" Version="6.1.1" />

docs/content/Getting Started.fsx

@@ -34,6 +34,13 @@ dotnet add package FSharp.Analyzers.SDK
 paket add FSharp.Analyzers.SDK
 ```
 
+The `FSharp.Analyzers.SDK` takes a dependency on [FSharp.Compiler.Service](https://www.nuget.org/packages/FSharp.Compiler.Service/), which has a strict dependency on `FSharp.Core`.  
+It is considered a best practice to use the correct `FSharp.Core` version and not the implicit one from the SDK.
+
+```xml
+<PackageReference Update="FSharp.Core" Version="7.0.400" />
+```
+
 ## First analyzer
 
 An [Analyzer<'TContext>](../reference/fsharp-analyzers-sdk-analyzer-1.html) is a function that takes a `Context` and returns a list of `Message`.  

src/FSharp.Analyzers.Cli/Program.fs

@@ -1,5 +1,6 @@
 open System
 open System.IO
+open System.Runtime.Loader
 open FSharp.Compiler.CodeAnalysis
 open FSharp.Compiler.Text
 open Argu
@@ -55,12 +56,18 @@ let printInfo (fmt: Printf.TextWriterFormat<'a>) : 'a =
     else
         unbox (mkKn typeof<'a>)
 
-let printError text arg =
+let printError (text: Printf.TextWriterFormat<('a -> unit)>) (arg: 'a) : unit =
     Console.ForegroundColor <- ConsoleColor.Red
     printf "Error : "
     printfn text arg
     Console.ForegroundColor <- origForegroundColor
 
+let printError2 (text: string) : unit =
+    Console.ForegroundColor <- ConsoleColor.Red
+    printf "Error : "
+    Console.WriteLine(text)
+    Console.ForegroundColor <- origForegroundColor
+
 let loadProject toolsPath projPath =
     async {
         let loader = WorkspaceLoader.Create(toolsPath)
@@ -277,6 +284,21 @@ let main argv =
                     printInfo "%s" msg
         }
 
+    AssemblyLoadContext.Default.add_Resolving (fun ctx assemblyName ->
+        if assemblyName.Name = "FSharp.Core" then
+            let msg =
+                $"""Could not load FSharp.Core %A{assemblyName.Version}. The expected assembly version of FSharp.Core is %A{Utils.currentFSharpCoreVersion}.
+Consider adding <PackageReference Update="FSharp.Core" Version="<CorrectVersion>" /> to your .fsproj.
+The correct version can be found over at https://www.nuget.org/packages/FSharp.Analyzers.SDK#dependencies-body-tab.
+"""
+
+            printError2 msg
+        else
+            printError2 $"Could not load %s{assemblyName.Name} %A{assemblyName.Version}."
+
+        exit 1
+    )
+
     let client =
         Client<CliAnalyzerAttribute, CliContext>(logger, Set.ofList excludeAnalyzers)
 

src/FSharp.Analyzers.SDK/FSharp.Analyzers.SDK.fs

@@ -180,6 +180,15 @@ module Utils =
     let currentFSharpAnalyzersSDKVersion =
         Assembly.GetExecutingAssembly().GetName().Version
 
+    let currentFSharpCoreVersion =
+        let currentAssembly = Assembly.GetExecutingAssembly()
+        let references = currentAssembly.GetReferencedAssemblies()
+        let fc = references |> Array.tryFind (fun ra -> ra.Name = "FSharp.Core")
+
+        match fc with
+        | None -> failwith "FSharp.Core could not be found as a reference assembly of the SDK."
+        | Some fc -> fc.Version
+
     let createContext
         (checkProjectResults: FSharpCheckProjectResults)
         (fileName: string)

src/FSharp.Analyzers.SDK/FSharp.Analyzers.SDK.fsi

@@ -161,6 +161,7 @@ module Utils =
         | SourceText of ISourceText
 
     val currentFSharpAnalyzersSDKVersion: Version
+    val currentFSharpCoreVersion: Version
 
     val createFCS: documentSource: option<string -> Async<option<ISourceText>>> -> FSharpChecker