Proposal is to dump ./configure options to have an output like below:
```
LIBZMQ (x86_64) - ./configure options to build 'LIBZMQ':
> --quiet
> TOOLCHAIN=/tmp/android-ndk-r25/toolchains/llvm/prebuilt/linux-x86_64
> CC=/tmp/android-ndk-r25/toolchains/llvm/prebuilt/linux-x86_64/bin/x86_64-linux-android21-clang
> CXX=/tmp/android-ndk-r25/toolchains/llvm/prebuilt/linux-x86_64/bin/x86_64-linux-android21-clang++
> LD=/tmp/android-ndk-r25/toolchains/llvm/prebuilt/linux-x86_64/bin/ld
> AS=/tmp/android-ndk-r25/toolchains/llvm/prebuilt/linux-x86_64/bin/llvm-as
> AR=/tmp/android-ndk-r25/toolchains/llvm/prebuilt/linux-x86_64/bin/llvm-ar
> RANLIB=/tmp/android-ndk-r25/toolchains/llvm/prebuilt/linux-x86_64/bin/llvm-ranlib
> STRIP=/tmp/android-ndk-r25/toolchains/llvm/prebuilt/linux-x86_64/bin/llvm-strip
> CFLAGS= -D_GNU_SOURCE -D_REENTRANT -D_THREAD_SAFE
> CPPFLAGS= -I/builds/CrisalidBox/zproject-android-testing/libzmq/builds/android/prefix/x86_64/include
> CXXFLAGS=
> LDFLAGS=-L/builds/CrisalidBox/zproject-android-testing/libzmq/builds/android/prefix/x86_64/lib -L/tmp/android-ndk-r25/sources/cxx-stl/llvm-libc++/libs/x86_64
> LIBS=-lc -ldl -lm -llog -lc++_shared
> PKG_CONFIG_LIBDIR=/tmp/android-ndk-r25/prebuilt/linux-x86_64/lib/pkgconfig
> PKG_CONFIG_PATH=/builds/CrisalidBox/zproject-android-testing/libzmq/builds/android/prefix/x86_64/lib/pkgconfig
> PKG_CONFIG_SYSROOT_DIR=/tmp/android-ndk-r25/toolchains/llvm/prebuilt/linux-x86_64/sysroot
> PKG_CONFIG_DIR=
> --with-sysroot=/tmp/android-ndk-r25/toolchains/llvm/prebuilt/linux-x86_64/sysroot
> --host=x86_64-linux-android
> --prefix=/builds/CrisalidBox/zproject-android-testing/libzmq/builds/android/prefix/x86_64
> --disable-curve
> --without-docs
```
Note:
This mechanism is currently in use to identify/fix a bug in a recent PR for NDK update.
This mechanism is added before every call of `./configure`.
To be reported to CZMQ/ZYRE (via ZPROJECT).
Seen in the code:
```
function android_build_verify_so {
...
for dep_soname do
if [[ $elfoutput != *"library: [${dep_soname}]"* ]]; then
ANDROID_BUILD_FAIL+=("Library ${soname} was expected to be linked to library with soname:")
ANDROID_BUILD_FAIL+=(" ${dep_soname}")
fi
done
```
The `for xxx` syntax is wrong, most probably a typo somewhere.
Solution: Fix & complete the `for xxx` loop.
Tested with & without LIBSODIUM (only available dependent library for LIBZMQ).
Note: The same has to be done in ZPROJECT, for CZMQ & ZYRE.
Solution: Modify the build scripts so the user can specify the platform
for which to build, e.g. `./build.sh arm`. This approach originally
significantly reduces the parameters which have to be set before running
the script.
Further the build process is documented in a README now.
Solution: Migrate build scripts from Android NDK r11c to r20.
- Standalone toolchain
- Migration from GCC to Clang
- Migration from libgnustl to libc++
- Dropped support for API level below 16 (Android 4.1), previously it was API level 9 (Android 2.3)
- Dropped support for mips architecture
- The build script now start the build of all 4 Android architectures (arm, arm64, x86, x86_64)
Solution: set the appropriate options, environment variables and paths
so that the host pkg-config files are ignored, and the target ones are
used instead (if any)
