Fix build.

Set BUILD_EMULATOR to true when HOST_OS is linux.
Disable the emulator package target if BUILD_EMULATOR is not true.

Change-Id: I8987c0a091622baa0e861b451e635c4ddb148b29

CleanSpec.mk

@@ -125,6 +125,8 @@ $(call add-clean-step, rm -rf $(PRODUCT_OUT)/system/build.prop)
 # Now we switched to build against Mac OS X SDK 10.6
 $(call add-clean-step, rm -rf $(OUT_DIR)/host/darwin-x86/obj)
 
+$(call add-clean-step, rm -f $(OUT_DIR)/versions_checked.mk)
+
 # ************************************************
 # NEWER CLEAN STEPS MUST BE AT THE END OF THE LIST
 # ************************************************

core/Makefile

@@ -1298,7 +1298,7 @@ dalvikfiles: $(INTERNAL_DALVIK_MODULES)
 
 # -----------------------------------------------------------------
 # The emulator package
-
+ifeq ($(BUILD_EMULATOR),true)
 INTERNAL_EMULATOR_PACKAGE_FILES += \
         $(HOST_OUT_EXECUTABLES)/emulator$(HOST_EXECUTABLE_SUFFIX) \
         prebuilts/qemu-kernel/$(TARGET_ARCH)/kernel-qemu \
@@ -1314,6 +1314,7 @@ $(INTERNAL_EMULATOR_PACKAGE_TARGET): $(INTERNAL_EMULATOR_PACKAGE_FILES)
 	@echo "Package: $@"
 	$(hide) zip -qj $@ $(INTERNAL_EMULATOR_PACKAGE_FILES)
 
+endif
 # -----------------------------------------------------------------
 # Old PDK stuffs, retired
 # The pdk package (Platform Development Kit)

core/main.mk

@@ -187,7 +187,9 @@ MACOSX_SDK := /Developer/SDKs/MacOSX$(MSDK).sdk
 ifeq ($(strip $(wildcard $(MACOSX_SDK))),)
   BUILD_EMULATOR := false
 endif
-endif
+else   # HOST_OS is not darwin
+  BUILD_EMULATOR := true
+endif  # HOST_OS is darwin
 
 $(shell echo 'VERSIONS_CHECKED := $(VERSION_CHECK_SEQUENCE_NUMBER)' \
         > $(OUT_DIR)/versions_checked.mk)