"No rule to make target" when compiling NDK sources on Windows with Gradle

Question

I am attempting a basic Android app containing an NDK library built from source. I get the following error when building :

gradlew assembleArm
:myapp:compileArmDebugNdk
make.exe: *** No rule to make target
`C:\Projects\MyApp\myapp\build\ndk\arm\debug\obj/local/armeabi-v7a/objs-debug/process/C_\Projects\MyApp\myapp\src\main\jni', needed by `C:\Projects\MyApp\myapp\build\ndk\arm\debug\obj/local/armeabi-v7a/objs-debug/process/C_\Projects\MyApp\myapp\src\main\jni\process.o'.  Stop.
:myapp:compileArmDebugNdk FAILED

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':myapp:compileArmDebugNdk'.
> com.android.ide.common.internal.LoggedErrorException: Failed to run command:
    C:\android-ndk-r9d\ndk-build.cmd NDK_PROJECT_PATH=null APP_BUILD_SCRIPT=C:\Projects\MyApp\myapp\build\ndk\arm\debug\Android.mk APP_PLATFORM=android-18 NDK_OUT=C:\Projects\MyApp\myapp\build\ndk\arm\debug\obj NDK_LIBS_OUT=C:\Projects\MyApp\myapp\build\ndk\arm\debug\lib NDK_DEBUG=1 APP_STL=stlport_static APP_ABI=armeabi-v7a

The target path looks odd to me. The makefile generated by gradle looks like this:

LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)

LOCAL_MODULE := process
LOCAL_CFLAGS := -DANDROID_NDK
LOCAL_SRC_FILES := \
C:\Projects\MyApp\myapp\src\main\jni\process.cpp \

LOCAL_C_INCLUDES += C:\Projects\MyApp\myapp\src\main\jni
LOCAL_C_INCLUDES += C:\Projects\MyApp\myapp\src\arm\jni
LOCAL_C_INCLUDES += C:\Projects\MyApp\myapp\src\debug\jni
LOCAL_C_INCLUDES += C:\Projects\MyApp\myapp\src\armDebug\jni

include $(BUILD_SHARED_LIBRARY)

I am using

• gradle plugin 0.9
• NDK r9d for Windows x64

I'd appreciate any help. I've got some experience with gradle and GNU build tools but I'm new to Android and the NDK.

Answer 1

Like Selvin said, it should be fine as soon as you add another source file. Even an empty one will do the trick.

I've filled a bug report with more information: https://code.google.com/p/android/issues/detail?id=66937

Answer 2

Just go to Terminal and write

1: cd your_path_to\src\main\jni

2: ndk-build