List of best mirrors for IP address 3.140.185.250, located in an unknown country.
I am very sorry, but no mirror was found. Feel free to download directly:
http://mirrordirector-mb.raspbian.org/multiarch/pool/main/l/llvm-toolchain-6.0/llvm-6.0-tools-dbgsym_6.0.1-10+rpi1_arm64.deb