Another fix

Dockerfile-ubuntu2004

@@ -34,6 +34,8 @@ RUN wget https://github.com/Kitware/CMake/releases/download/v3.21.3/cmake-3.21.3
 # Fix some weird linker issue CAF build runs into. (fails to link -lc++abi)
 RUN cp -prv /usr/lib/llvm-12/lib/libc++abi.so.1.0 /usr/lib/llvm-12/lib/libc++abi.so
 
+RUN cp -prv /usr/lib/llvm-12/lib/libunwind.so.1.0 /usr/lib/llvm-12/lib/libunwind.so
+
 COPY switch-to-latest-clang /usr/local/bin/switch-to-latest-clang
 
 RUN chmod +x /usr/local/bin/switch-to-latest-clang