Fix newest version of CAF build with clang v9.

Dockerfile-ubuntu1804

     rm -rf cmake-3.16.2 && \
     rm -rf cmake-3.16.2.tar.gz
 
+# Fix some weird linker issue CAF build runs into. (fails to link -lc++abi)
+RUN cp -prv /usr/lib/llvm-9/lib/libc++abi.so.1.0 /usr/lib/llvm-9/lib/libc++abi.so
+
 CMD "/bin/bash"

caf/Makefile

 		--no-tools \
 		--no-python && \
 	pushd build && \
-	mkdir build && \
+	mkdir -p build && \
 	cmake  \
 		-DCMAKE_INSTALL_PREFIX=$$PWD/caf_out \
 		-DCAF_BUILD_STATIC=yes \
 		-DCAF_BUILD_STATIC_ONLY=yes \
-		-DCAF_NO_AUTO_LIBCPP=yes \
 		-DCAF_NO_EXAMPLES=yes \
 		-DCAF_NO_UNIT_TESTS=yes \
 		.. && \
 	make -j $$(nproc) && \
 	make install
+		#-DCAF_NO_AUTO_LIBCPP=yes \
 	#GLIBCXX_USE_CXX11_ABI=1 CMAKE_CXX_FLAGS="-std=c++17 -stdlib=libc++" make -j $$(nproc) && \
 	#make install
 	#CMAKE_CXX_FLAGS="-std=c++17 -stdlib=libc++" make -j $$(nproc) && \