Use vswhere to search for vs2017+ install directory to locate msbuild

src/app/Fake.Core.Environment/Environment.fs

@@ -145,6 +145,9 @@ module Environment =
         | _ -> environVar "ProgramFiles"
         |> fun detected -> if isNull detected then @"C:\Program Files (x86)\" else detected
 
+    /// The path to vswhere utility which helps determine VS2017+ installation directory
+    let VSWhere = ProgramFilesX86 + @"\Microsoft Visual Studio\Installer\vswhere.exe"
+
     /// The system root environment variable. Typically "C:\Windows"
     let SystemRoot = environVar "SystemRoot"
 

src/app/Fake.DotNet.MSBuild/MSBuild.fs

@@ -87,7 +87,27 @@ module private MSBuildExe =
     items |> Seq.map (fun f -> f.Version, f.Paths) |> Map.ofSeq
 
   let private getAllKnownPaths =
-    (knownMSBuildEntries |> List.collect (fun m -> m.Paths)) @ oldMSBuildLocations
+    let getVSPathFromVSWhere ver =
+        try
+            Process.execWithResult (fun proc ->
+                { proc with
+                    FileName = Fake.Core.Environment.VSWhere
+                    Arguments = sprintf "-version %s -property installationPath" ver })
+                TimeSpan.MaxValue
+            |> fun processResult ->
+                if processResult.OK then
+                    processResult.Messages |> List.tryHead 
+                    |> Option.map(fun vsRoot -> sprintf @"%s\MSBuild\%s\Bin" vsRoot ver) 
+                else Option.None
+        with _ -> Option.None
+
+    let paths =
+      (knownMsBuildEntries |> List.collect (fun m -> m.Paths)) @ oldMsBuildLocations
+
+    let version = Environment.environVarOrNone "VisualStudioVersion"
+    Option.bind getVSPathFromVSWhere version
+    |> Option.fold(fun paths path -> path :: paths) paths
+
 
   /// Versions of Mono prior to this one have faulty implementations of MSBuild
   /// NOTE: in System.Version 5.0 >= 5.0.0.0 is false while 5.0.0.0 >= 5.0 is true...

src/legacy/FakeLib/EnvironmentHelper.fs

@@ -151,6 +151,11 @@ let ProgramFiles =
 [<System.Obsolete("Use Fake.Core.Environment instead (FAKE0001 - package: Fake.Core.Environment)")>]
 let ProgramFilesX86 = Environment.GetFolderPath Environment.SpecialFolder.ProgramFilesX86
 
+/// The path to vswhere utility which helps determine VS2017+ installation directory
+[<System.Obsolete("Use Fake.Core.Environment instead (FAKE0001 - package: Fake.Core.Environment)")>]
+let VSWhere = ProgramFilesX86 + @"\Microsoft Visual Studio\Installer\vswhere.exe"
+
+
 /// The system root environment variable. Typically "C:\Windows"
 [<System.Obsolete("Use Fake.Core.Environment instead (FAKE0001 - package: Fake.Core.Environment)")>]
 let SystemRoot = environVar "SystemRoot"

src/legacy/FakeLib/MSBuildHelper.fs

@@ -105,6 +105,17 @@ let msBuildExe =
             ]
             defaultArg (sources |> List.choose id |> List.tryHead) "xbuild"
         | false, _ ->
+            let getVSPathFromVSWhere ver =
+                try 
+                    ExecProcessAndReturnMessages(fun info ->
+                        info.FileName <- VSWhere
+                        info.Arguments <- sprintf "-version %s -property installationPath" ver) TimeSpan.MaxValue
+                    |> fun processResult ->
+                           if processResult.OK then
+                               processResult.Messages.ToArray() |> Array.tryHead
+                               |> Option.map(fun vsRoot -> sprintf @"%s\MSBuild\%s\Bin" vsRoot ver)
+                           else Option.None
+                with _ -> Option.None
 
             let configIgnoreMSBuild =
                 if "true".Equals(ConfigurationManager.AppSettings.["IgnoreMSBuild"], StringComparison.OrdinalIgnoreCase)
@@ -113,8 +124,12 @@ let msBuildExe =
             let findOnVSPathsThenSystemPath =
                 let dict = toDict knownMsBuildEntries
                 let vsVersionPaths =
-                    defaultArg (EnvironmentHelper.environVarOrNone "VisualStudioVersion" |> Option.bind dict.TryFind) getAllKnownPaths
-                    |> List.map ((@@) ProgramFilesX86)
+                    let version = EnvironmentHelper.environVarOrNone "VisualStudioVersion"
+                    let paths =
+                        defaultArg (version |> Option.bind dict.TryFind) getAllKnownPaths
+                        |> List.map ((@@) ProgramFilesX86)
+                    Option.bind getVSPathFromVSWhere version
+                    |> Option.fold(fun paths path -> path :: paths) paths
 
                 ProcessHelper.tryFindFileInDirsThenPath vsVersionPaths "MSBuild.exe"