Windows: replace "where" by "tools\which"

- silent which.exe in case of error
Otherwise you'll get the too verbose path

makefiles/Makefile.csharp.mk

@@ -14,7 +14,7 @@ CSHARP_COMPILER ?= csc.exe
 ifneq ($(PATH_TO_CSHARP_COMPILER),)
 CSHARP_EXECUTABLE := "$(PATH_TO_CSHARP_COMPILER)"
 else
-CSHARP_EXECUTABLE := "$(shell tools\\which.exe $(CSHARP_COMPILER))"
+CSHARP_EXECUTABLE := "$(shell tools\\which.exe $(CSHARP_COMPILER) 2>nul)"
 endif
 else # UNIX
 CSHARP_COMPILER ?= mcs
@@ -598,7 +598,7 @@ rcsfz: $(BIN_DIR)/csfz$(CLR_EXE_SUFFIX).exe
 
 ifeq ($(SYSTEM),win)
 NUGET_COMPILER ?= nuget.exe
-NUGET_EXECUTABLE := $(shell tools\\which.exe $(NUGET_COMPILER))
+NUGET_EXECUTABLE := $(shell tools\\which.exe $(NUGET_COMPILER) 2>nul)
 else #UNIX
 NUGET_COMPILER ?= nuget
 NUGET_EXECUTABLE := $(shell which $(NUGET_COMPILER))

makefiles/Makefile.fsharp.mk

@@ -15,7 +15,7 @@ CLEAN_FILES=$(FSHARP_ORTOOLS_DLL_NAME).*
 # Check for required build tools
 ifeq ($(SYSTEM), win)
 FSHARP_COMPILER := fsc.exe
-FSHARP_EXECUTABLE := $(shell tools\\which.exe $(FSHARP_COMPILER))
+FSHARP_EXECUTABLE := $(shell tools\\which.exe $(FSHARP_COMPILER) 2>nul)
 FLAG_PREFIX := /
 else # UNIX
 FSHARP_COMPILER := fsharpc

makefiles/Makefile.port.mk

@@ -199,11 +199,11 @@ ifeq ($(SYSTEM),win)
 
   #Detect csc
   ifeq ($(PATH_TO_CSHARP_COMPILER),)
-    DETECTED_CSC_BINARY := $(shell where /F csc | tools\\sed.exe -n "/\".*\"/{p;q;}" | tools\\sed "s/\"//g")
+    DETECTED_CSC_BINARY := $(shell tools\\which.exe csc 2>nul)
     ifeq ($(DETECTED_CSC_BINARY),)
       SELECTED_CSC_BINARY = PATH_TO_CSHARP_COMPILER =\# csc was not found. Set this variable to the path of csc to build the chsarp files. (ex: PATH_TO_CSHARP_COMPILER = C:\Program Files (x86)\MSBuild\14.0\Bin\amd64\csc.exe)
     else
-      SELECTED_CSC_BINARY = PATH_TO_CSHARP_COMPILER = $(DETECTED_CSC_BINARY)
+      SELECTED_CSC_BINARY =\#PATH_TO_CSHARP_COMPILER =
     endif
   else
     SELECTED_CSC_BINARY = PATH_TO_CSHARP_COMPILER = $(PATH_TO_CSHARP_COMPILER)

makefiles/Makefile.python.mk

@@ -14,9 +14,9 @@ OR_TOOLS_PYTHONPATH = $(OR_ROOT_FULL)$(CPSEP)$(OR_ROOT_FULL)$Sdependencies$Ssour
 ifeq ($(SYSTEM),win)
 PYTHON_COMPILER ?= python.exe
 ifneq ($(WINDOWS_PATH_TO_PYTHON),)
-PYTHON_EXECUTABLE := $(shell where "$(WINDOWS_PATH_TO_PYTHON):$(PYTHON_COMPILER)")
+	PYTHON_EXECUTABLE := $(shell set PATH="$(WINDOWS_PATH_TO_PYTHON):%PATH%" && tools\\which.exe $(PYTHON_COMPILER) 2>nul)
 else
-PYTHON_EXECUTABLE := $(shell tools\\which.exe $(PYTHON_COMPILER))
+PYTHON_EXECUTABLE := $(shell tools\\which.exe $(PYTHON_COMPILER) 2>nul)
 endif
 SET_PYTHONPATH = @set PYTHONPATH=$(OR_TOOLS_PYTHONPATH) &&
 else # UNIX

makefiles/Makefile.win.mk

@@ -41,6 +41,7 @@ MKDIR_P = tools\mkdir.exe -p
 COPY = copy
 TOUCH = tools\touch.exe
 SED = tools\sed.exe
+WHICH = tools\which.exe
 CMAKE = cmake
 ARCHIVE_EXT = .zip
 FZ_EXE = fzn-or-tools$E