同学们在往 Android 手机里灌一些原生 ELF 程序（如 netperf 等等）的时候会不会遇到这样的编译困难：

Android NDK: Your APP_BUILD_SCRIPT points to an unknown file: $NDK_PROJECT_PATH/jni/Android.mk

而同时这个 project 的 Android.mk 在根目录下？

其实解决这个问题的正确办法是编辑 NDK 目录下的 build/core/default-application.mk 文件，如下：

# Copyright (C) 2010 The Android Open Source Project
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#

# This is the default Application.mk that is being used for applications
# that don't provide $PROJECT_PATH/jni/Application.mk
#
APP_PROJECT_PATH := $(NDK_PROJECT_PATH)

# We expect the build script to be located here
APP_BUILD_SCRIPT := $(APP_PROJECT_PATH)/jni/Android.mk

把最后一行该死的“ jni ”去掉就行了。

P.S.: https://android.googlesource.com/ 里面 platform/external 下面的东西都老有用了