Building libraries(MySQL) on new versions of NDK(r18b)

[MazyCrazy]

Hello.
I'm new to Android development.
I need to build MySQL for Android. I found a detailed and working guide how to do it for Android NDK r10e. The problem is that I use some kind of framework (Qt 5.12.3) that only works with recent versions of the Android NDK, for example r18b. In this and newer versions, the file structure has been greatly changed, and now I cannot find the headers, libraries and programs I need.

Here are the variables that I need to declare to successfully build all the libraries (libiconv, OpenSSL, MariaDB):

export ANDROID_NDK_ROOT=/c/android-ndk-r10e
export SR="$ANDROID_NDK_ROOT"/platforms/android-19/arch-arm
export BR="$ANDROID_NDK_ROOT"/toolchains/arm-linux-androideabi-4.9/prebuilt/windows-x86_64/bin/arm-linux-androideabi-
export CPP="$BR"cpp
export AR="$BR"ar
export STRIP="$BR"strip
export RANLIB="$BR"ranlib
export LINKER="$BR"ld
export OBJDUMP="$BR"objdump
export CC="$BR"gcc
export CFLAGS="--sysroot=$SR"
export CPPFLAGS="$CFLAGS"
export C_INCLUDE_PATH=$SR/include
export ANDROID_DEV=$SR/usr
export MAKEDEPPROG="$CC -M"

About problem, for example, in the $BR folder there are no more necessary compiler programs, and there are no headers in the $SR folder.
Note: $SR - "sysroot", $BR - common path to binaries in old Anroid NDK versions.

Thanks for help.