Created a Qt project with this main:

#include "QDialog"
#include <QApplication>
#include <assert.h>

int main(int argc, char *argv[])
{
    assert( false );

    QApplication a(argc, argv);
    QDialog dlg;
    dlg.show();

    return a.exec();
}

Compile in Debug targeting Windows (MSVC2015), it asserts on run.
Compile in Release targeting Windows (MSVC2015), it does not assert on run.

Compile in Debug targeting Android (armv7), it asserts on run.
Compile in Release targetting Android (armv7), it asserts on run.

assert must be removed in Release builds. Apparently NDEBUG is not set upon compilation.

This is critical (assert could make Release applications crash!