use FAKE for documentation generation.

build.template

@@ -182,22 +182,52 @@ Target "PublishNuget" (fun _ ->
 // --------------------------------------------------------------------------------------
 // Generate the documentation
 
+
+let fakePath = "packages" @@ "FAKE" @@ "tools" @@ "FAKE.exe"
+let fakeStartInfo script workingDirectory args fsiargs environmentVars =
+    (fun (info: System.Diagnostics.ProcessStartInfo) ->
+        info.FileName <- fakePath
+        info.Arguments <- sprintf "%s --fsiargs -d:FAKE %s \"%s\"" args fsiargs script
+        info.WorkingDirectory <- workingDirectory
+        let setVar k v =
+            info.EnvironmentVariables.[k] <- v
+        for (k, v) in environmentVars do
+            setVar k v
+        setVar "MSBuild" msBuildExe
+        setVar "GIT" Git.CommandHelper.gitPath
+        setVar "FSI" fsiPath)
+
+/// Run the given buildscript with FAKE.exe
+let executeFAKEWithOutput workingDirectory script fsiargs envArgs =
+    let exitCode =
+        ExecProcessWithLambdas
+            (fakeStartInfo script workingDirectory "" fsiargs envArgs)
+            TimeSpan.MaxValue false ignore ignore
+    System.Threading.Thread.Sleep 1000
+    exitCode
+
+// Documentation
+let buildDocumentationTarget fsiargs target =
+    trace (sprintf "Building documentation (%s), this could take some time, please wait..." target)
+    let exit = executeFAKEWithOutput "docs/tools" "generate.fsx" fsiargs ["target", target]
+    if exit <> 0 then
+        failwith "generating reference documentation failed"
+    ()
+
 Target "GenerateReferenceDocs" (fun _ ->
-    if not <| executeFSIWithArgs "docs/tools" "generate.fsx" ["--define:RELEASE"; "--define:REFERENCE"] [] then
-      failwith "generating reference documentation failed"
+    buildDocumentationTarget "-d:RELEASE" -d:REFERENCE" "Default"
 )
 
 let generateHelp' fail debug =
     let args =
-        if debug then ["--define:HELP"]
-        else ["--define:RELEASE"; "--define:HELP"]
-    if executeFSIWithArgs "docs/tools" "generate.fsx" args [] then
+        if debug then "--define:HELP"
+        else "--define:RELEASE --define:HELP"
+    try
+        buildDocumentationTarget args "Default"
         traceImportant "Help generated"
-    else
-        if fail then
-            failwith "generating help documentation failed"
-        else
-            traceImportant "generating help documentation failed"
+    with
+    | e when not fail ->
+        traceImportant "generating help documentation failed"
 
 let generateHelp fail =
     generateHelp' fail false