# export NDK (using NDK 19c)
export ANDROID_NDK_TOOLCHAIN='/home/<username>/android/android-ndk-r19c/toolchains/llvm/prebuilt/linux-x86_64'

# script 1
./configure CFLAGS="-g -O2" LDFLAGS="-g -O2" --prefix=`pwd`/ecl-android-host --disable-c99complex CC=clang
make
make install
rm -r build

# script 2
export AR=$ANDROID_NDK_TOOLCHAIN/bin/aarch64-linux-android-ar
export AS=$ANDROID_NDK_TOOLCHAIN/bin/aarch64-linux-android-as
export CC=$ANDROID_NDK_TOOLCHAIN/bin/aarch64-linux-android21-clang
export LD=$ANDROID_NDK_TOOLCHAIN/bin/aarch64-linux-android-ld
export RANLIB=$ANDROID_NDK_TOOLCHAIN/bin/aarch64-linux-android-ranlib
export STRIP=$ANDROID_NDK_TOOLCHAIN/bin/aarch64-linux-android-strip
export ECL_TO_RUN=`pwd`/ecl-android-host/bin/ecl
./configure --host=aarch64-linux-android \
            --prefix=`pwd`/ecl-android \
            --disable-c99complex \
            --with-cross-config=`pwd`/src/util/android-arm64.cross_config
make
make install