Execution failed for task ':app:externalNativeBuildDebug'

　　升级了AndroidStudio到3.4之后，之前的项目开始出现千奇百怪的问题——

org.gradle.internal.UncheckedException: Build command failed.
Error while executing process D:\Android\SDK\cmake\3.6.4111459\bin\cmake.exe with arguments {--build C:\Users\zzulj\Desktop\HeartRateDetection\app\.externalNativeBuild\cmake\debug\armeabi-v7a --target native-lib}
[1/6] Building CXX object CMakeFiles/native-lib.dir/src/main/cpp/native-lib.cpp.o
[2/6] Building CXX object CMakeFiles/native-lib.dir/src/main/cpp/transCodec.cpp.o
[3/6] Building CXX object CMakeFiles/native-lib.dir/src/main/cpp/SpO2.cpp.o
[4/6] Building CXX object CMakeFiles/native-lib.dir/src/main/cpp/snprintf.cpp.o
[5/6] Building CXX object CMakeFiles/native-lib.dir/src/main/cpp/HRD.cpp.o
[6/6] Linking CXX shared library ..\..\..\..\build\intermediates\cmake\debug\obj\armeabi-v7a\libnative-lib.so
...

　　调用cmake.exe时候出现问题，导致动态链接库无法链接，那么查看一下CMakeLists.txt配置文件，发现一个问题，NDK从开始的16r升级到现在的20之后，CMake也跟着升级了，但是CMakeLists的版本信息却没有对应的升级，于是修改字段——

cmake_minimum_required(VERSION 3.6.4111459)

　　问题解决。