According to an excellent developer, it's gcc bug.
The super valuable message by Lord Terminal
error: 'to_string' was not declared in this scope
What should I do?
Just edit this -> (ProjectName)/proj.android/jni/Application.mk# APP_STL := gnustl_static APP_STL := c++_static
Ref link
https://stackoverflow.com/questions/15569179https://stackoverflow.com/questions/12975341