Prevent user from cross-compiling the wrong target

Makefile

@@ -103,16 +103,32 @@ $(MODULEDIR)/theme.qt5.a: .FORCE
 	@$(MAKE) -C source/theme qt5
 
 $(MODULEDIR)/%.posix32.a: .FORCE
+ifneq ($(WIN32),true)
 	@$(MAKE) -C source/modules/$* posix32
+else
+	$(error Trying to build POSIX binaries with a Windows toolchain, this cannot work)
+endif
 
 $(MODULEDIR)/%.posix64.a: .FORCE
+ifneq ($(WIN32),true)
 	@$(MAKE) -C source/modules/$* posix64
+else
+	$(error Trying to build POSIX binaries with a Windows toolchain, this cannot work)
+endif
 
 $(MODULEDIR)/%.win32.a: .FORCE
+ifeq ($(WIN32),true)
 	@$(MAKE) -C source/modules/$* win32
+else
+	$(error Trying to build Windows binaries with a regular toolchain, this cannot work)
+endif
 
 $(MODULEDIR)/%.win64.a: .FORCE
+ifeq ($(WIN32),true)
 	@$(MAKE) -C source/modules/$* win64
+else
+	$(error Trying to build Windows binaries with a regular toolchain, this cannot work)
+endif
 
 $(MODULEDIR)/%.a: .FORCE
 	@$(MAKE) -C source/modules/$*

source/jackbridge/Makefile

@@ -42,17 +42,31 @@ OBJS_win32e   = $(OBJDIR)/JackBridgeExport.cpp.win32e.o
 
 # ----------------------------------------------------------------------------------------------------------------------------
 
-all:      $(MODULEDIR)/$(MODULENAME).a
-posix32:  $(MODULEDIR)/$(MODULENAME).posix32.a
-posix64:  $(MODULEDIR)/$(MODULENAME).posix64.a
-posix32e: $(MODULEDIR)/$(MODULENAME).posix32e.a
-posix64e: $(MODULEDIR)/$(MODULENAME).posix64e.a
+all: $(MODULEDIR)/$(MODULENAME).a
+
+ifeq ($(WIN32),true)
+posix32:
+posix64:
+posix32e:
+posix64e:
 win32:    $(MODULEDIR)/$(MODULENAME).win32.a
 win64:    $(MODULEDIR)/$(MODULENAME).win64.a
 win32e:   $(MODULEDIR)/$(MODULENAME).win32e.a
 win64e:   $(MODULEDIR)/$(MODULENAME).win64e.a
+wine32:
+wine64:
+else
+posix32:  $(MODULEDIR)/$(MODULENAME).posix32.a
+posix64:  $(MODULEDIR)/$(MODULENAME).posix64.a
+posix32e: $(MODULEDIR)/$(MODULENAME).posix32e.a
+posix64e: $(MODULEDIR)/$(MODULENAME).posix64e.a
+win32:
+win64:
+win32e:
+win64e:
 wine32:   $(MODULEDIR)/$(MODULENAME)-wine32.dll$(LIB_EXT)
 wine64:   $(MODULEDIR)/$(MODULENAME)-wine64.dll$(LIB_EXT)
+endif
 
 # ----------------------------------------------------------------------------------------------------------------------------