Allow to set process encoding - fixes #1215

src/app/FakeLib/ProcessHelper.fs

@@ -57,6 +57,14 @@ type ProcessResult =
           Messages = messages
           Errors = errors }
 
+/// If set to true the ProcessHelper will start all processes with a custom ProcessEncoding.
+/// If set to false (default) only mono processes will be changed.
+let mutable AlwaysSetProcessEncoding = false
+
+/// The ProcessHelper will start all processes with this encoding if AlwaysSetProcessEncoding is set to true.
+/// If AlwaysSetProcessEncoding is set to false (default) only mono processes will be changed.
+let mutable ProcessEncoding = Encoding.UTF8
+
 /// Runs the given process and returns the exit code.
 /// ## Parameters
 ///
@@ -77,9 +85,9 @@ let ExecProcessWithLambdas configProcessStartInfoF (timeOut : TimeSpan) silent e
     if silent then
         proc.StartInfo.RedirectStandardOutput <- true
         proc.StartInfo.RedirectStandardError <- true
-        if isMono then
-            proc.StartInfo.StandardOutputEncoding <- Encoding.UTF8
-            proc.StartInfo.StandardErrorEncoding  <- Encoding.UTF8
+        if isMono || AlwaysSetProcessEncoding then
+            proc.StartInfo.StandardOutputEncoding <- ProcessEncoding
+            proc.StartInfo.StandardErrorEncoding  <- ProcessEncoding
         proc.ErrorDataReceived.Add(fun d ->
             if d.Data <> null then errorF d.Data)
         proc.OutputDataReceived.Add(fun d ->