Error while trying to build a custom template : os_android.cpp

Question

Godot version : 3.2
Android-ndk : 21b

When trying to build a custom template for android with scons, i'm getting an error related to os_android.cpp :

 scons: Reading SConscript files ...

Building for Android (armv7) (with NEON)

Checking for C header file mntent.h... (cached) yes

scons: done reading SConscript files.

scons: Building targets ...

[Initial build] Compiling shared ==> platform/android/osandroid.cpp

In file included from platform/android/osandroid.cpp:35:

In file included from ./drivers/gles2/rasterizergles2.h:34:

In file included from ./drivers/gles2/rasterizercanvasgles2.h:34:

In file included from ./drivers/gles2/rasterizerstoragegles2.h:40:

./core/ridowner.h:301:80: error: use of typeid requires -frtti

                                printerror("ERROR: " + itos(alloccount) + " RID allocations of type '" + typeid(T).name() + "' were leaked at exit.");

                                                                                                           ^

In file included from platform/android/osandroid.cpp:35:

In file included from ./drivers/gles2/rasterizergles2.h:34:

In file included from ./drivers/gles2/rasterizercanvasgles2.h:34:

./drivers/gles2/rasterizerstoragegles2.h:41:10: fatal error: 'shaders/copy.glsl.gen.h' file not found

"#"include "shaders/copy.glsl.gen.h"

         ^~~~~~~~~~~~~~~~~~~~~~~~~

2 errors generated.

scons: *** [platform/android/os_android.os] Error 1

scons: building terminated because of errors.

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